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ETH Zurich
Marianne Wettstein
Professorship Crop Science
LFW, C 55.1
Universitätstrasse 2
8092 Zürich
Switzerland

Fax: +41 44 632 11 43

Group of Crop Science

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, Jansen, Marcus, Pinto, Francisco, Nagel, Kerstin A., van Dusschoten, Dagmar, Fiorani, Fabio, Rascher, Uwe, Schneider, Heike U., Walter, Achim, Schurr, Ulrich, 2014 >>
Author(s): Jansen, Marcus, Pinto, Francisco, Nagel, Kerstin A., van Dusschoten, Dagmar, Fiorani, Fabio, Rascher, Uwe, Schneider, Heike U., Walter, Achim, Schurr, Ulrich
Title: Non-invasive Phenotyping Methodologies Enable the Accurate Characterization of Growth and Performance of Shoots and Roots
Abstract: Significant improvements of the resource-use efficiency of major crops are required to meet the growing demand of food and feed in the next decades in a sustainable way. Breeding for new varieties and modern crop management aims at obtaining higher and more stable yields by optimizing plant structure and function under different environmental conditions. The development and application of non-invasive methods to estimate plant parameters underlying heritable traits are key enabling components. To address this demand, recently an increasing number of imaging technologies have started to be applied in plant research to analyze various types of genotype collections. Some of these applications are mature and suitable to be scaled-up to higher throughput; others require validation beyond proof-of-concept. In this chapter firstly we present an overview of available methods while stressing the current limitations to be taken into account for correct interpretation of the results. Secondly, we focus on three different case studies by our lab demonstrating the applicability of multispectral, fluorescence, and magnetic resonance imaging for various research questions applicable to controlled environments and to the field. Taken together, these case studies highlight that a variety of non-invasive plant phenotyping methods are essential tools not only for functional genomics, but also for plant selection and breeding. In addition, these experiments underline the need of developing methods tailored to different plant species and at various cultivation systems and scales.
Book title: Genomics of plant genetic resources
Pages: 173 - 203
ISBN: 978-94-007-7571-8, 978-94-007-7572-5
Publication date / Date received: 2014-01-01
Publication status: Dordrecht
Publication status: Published
Subjects: Bioinformatik, Biotechnologie und Genetik|Bioinformatics, Biotechnology and Genetics, Botanik |Botany , Acker- und Futterbau (inkl. Kultur- und Nutzpflanzen) | Crop and Fodder Farming (incl. Cultivated and Crop Plants), Plant phenotyping, Non-invasive imaging, Chlorophyll fluorescence, Hyperspectral imaging, Nuclear magnetic resonance imaging (MRI), Vegetation index
Language: English
Keyword: Plant phenotyping, Non-invasive imaging, Chlorophyll fluorescence, Hyperspectral imaging, Nuclear magnetic resonance imaging (MRI), Vegetation index
DBID source: CSV-
DOI: 10.1007/978-94-007-7572-5_8
Nebis system number: 009993291
, Strigens, Alexander, Freitag, Niclas M., Gilbert, Xavier, Grieder, Christoph, Riedelsheimer, Christian, Schrag, Tobias A., Messmer, Rainer, Melchinger, Albrecht E., 2013 >>
Author(s): Strigens, Alexander, Freitag, Niclas M., Gilbert, Xavier, Grieder, Christoph, Riedelsheimer, Christian, Schrag, Tobias A., Messmer, Rainer, Melchinger, Albrecht E.
Title: Association mapping for chilling tolerance in elite flint and dent maize inbred lines evaluated in growth chamber and field experiments
Abstract: Chilling sensitivity of maize is a strong limitation for its cultivation in the cooler areas of the northern and southern hemisphere because reduced growth in early stages impairs on later biomass accumulation. Efficient breeding for chilling tolerance is hampered by both the complex physiological response of maize to chilling temperatures and the difficulty to accurately measure chilling tolerance in the field under fluctuating climatic conditions. For this research, we used genome-wide association (GWA) mapping to identify genes underlying chilling tolerance under both controlled and field conditions in a broad germplasm collection of 375 maize inbred lines genotyped with 56 110 single nucleotide polymorphism (SNP). We identified 19 highly significant association signals explaining between 5.7 and 52.5% of the phenotypic variance observed for early growth and chlorophyll fluorescence parameters. The allelic effect of several SNPs identified for early growth was associated with temperature and incident radiation. Candidate genes involved in ethylene signalling, brassinolide, and lignin biosynthesis were found in their vicinity. The frequent involvement of candidate genes into signalling or gene expression regulation underlines the complex response of photosynthetic performance and early growth to climatic conditions, and supports pleiotropism as a major cause of co-locations of quantitative trait loci for these highly polygenic traits.
Published in: Plant, cell & environment
Volume: 36
Issue: 10
Pages: 1871 - 1887
ISSN: 0140-7791, 1365-3040
Publication date / Date received: 2013-01-01
Publication status: Oxford
Publication status: Published
Subjects: Botanik |Botany , Cold, Heterotic pools, QTL
Language: English
Review status: Peer reviewed
Keyword: Cold, Heterotic pools, QTL
DBID source: SCOPUS-84883556287
DOI: 10.1111/pce.12096
Nebis system number: 000003088
, Ruts, Tom, Matsubara, Shizue, Walter, Achim, 2013 >>
Author(s): Ruts, Tom, Matsubara, Shizue, Walter, Achim
Title: Synchronous high-resolution phenotyping of leaf and root growth in Nicotiana tabacum over 24-h periods with GROWMAP-plant
Abstract: Background: Root growth is highly responsive to temporal changes in the environment. On the contrary, diel (24 h) leaf expansion in dicot plants is governed by endogenous control and therefore its temporal pattern does not strictly follow diel changes in the environment. Nevertheless, root and shoot are connected with each other through resource partitioning and changing environments for one organ could affect growth of the other organ, and hence overall plant growth. Results: We developed a new technique, GROWMAP-plant, to monitor growth processes synchronously in leaf and root of the same plant with a high resolution over the diel period. This allowed us to quantify treatment effects on the growth rates of the treated and non-treated organ and the possible interaction between them. We subjected the root system of Nicotiana tabacum seedlings to three different conditions: constant darkness at 22 degrees C (control), constant darkness at 10 degrees C (root cooling), and 12 h/12 h light-dark cycles at 22 degrees C (root illumination). In all treatments the shoot was kept under the same 12 h/12 h light-dark cycles at 22 degrees C. Root growth rates were found to be constant when the root-zone environment was kept constant, although the root cooling treatment significantly reduced root growth. Root velocity was decreased after light-on and light-off events of the root illumination treatment, resulting in diel root growth rhythmicity. Despite these changes in root growth, leaf growth was not affected substantially by the root-zone treatments, persistently showing up to three times higher nocturnal growth than diurnal growth. Conclusion: GROWMAP-plant allows detailed synchronous growth phenotyping of leaf and root in the same plant. Root growth was very responsive to the root cooling and root illumination, while these treatments altered neither relative growth rate nor diel growth pattern in the seedling leaf. Our results that were obtained simultaneously in growing leaves and roots of the same plants corroborate the high sensitivity of root growth to the environment and the contrasting robustness of diel growth patterns in dicot leaves. Further, they also underpin the importance to carefully control the experimental conditions for root growth analysis to avoid or/and minimize artificial complications.
Published in: Plant Methods
Volume: 9
Pages: 2
ISSN: 1746-4811
Publication date / Date received: 2013-01-01
Publication status: Published
Subjects: Botanik |Botany , Biochemie, Molekularbiologie und Zellbiologie|Biochemistry, Molecular Biology and Cell Biology, Growth, Phenotyping, Diel, Diurnal, Temperature, Leaf, Shoot, Root, Nicotiana tabacum, Circadian
Language: English
Review status: Peer reviewed
Keyword: Growth, Phenotyping, Diel, Diurnal, Temperature, Leaf, Shoot, Root, Nicotiana tabacum, Circadian
DBID source: WOS-000315485500001
DOI: 10.1186/1746-4811-9-2
Nebis system number: 005576870
, Reimer, Regina, Stich, Benjamin, Melchinger, Albrecht E., Schrag, Tobias A., Sørensen, Anker P., Stamp, Peter, Hund, Andreas, 2013 >>
Author(s): Reimer, Regina, Stich, Benjamin, Melchinger, Albrecht E., Schrag, Tobias A., Sørensen, Anker P., Stamp, Peter, Hund, Andreas
Title: Root response to temperature extremes
Subtitle: Association mapping of temperate maize (Zea mays L)
Abstract: Little is known about the genetic control of the root architecture of maize (Zea mays L) and its response to temperature extremes. An association mapping panel, including 32 flint and 42 dent inbred lines, was characterized for root traits. The growth of axile and lateral roots was assessed non-destructively in growth pouches at 16°C (chilling), 28°C (control) and 36°C (heat). Association mapping was done using the PKOpt mixed-model associationmapping approach. Heat slowed down the development of seedling roots to a lesser extent than chilling, but differences between the heterotic groups were observed mainly at optimal temperature. Of 1,415 AFLP markers, 70 showed significant marker-trait associations and 90 showed significant marker-trait associations with temperature interaction effects. Compared to the flint lines, the dents showed stronger growth of axile roots, especially under optimal conditions, and carried more of the trait-increasing alleles for the length of axile roots. In contrast, the flints accumulated more root dry weight at low temperature and exclusively carried the alle les favoring tolerance to chilling. A combination of inbreds carrying alleles positive for performance under contrasting temperature conditions should lead to a complementary effect in the hybrid and would increase adaptation to a wider range of temperature.
Published in: Maydica
Volume: 58
Pages: 156 - 168
ISSN: 0025-6153
Publication date / Date received: 2013-01-01
Publication status: Bergamo
Publication status: Published
Subjects: Corn, Root growth, Cold, Heat, QTL
Language: English
Keyword: Corn, Root growth, Cold, Heat, QTL
DBID source: CSV-
Nebis system number: 003931813
, Planchamp, Chantal, Balmer, Dirk, Hund, Andreas, Mauch-Mani, Brigitte, 2013 >>
Author(s): Planchamp, Chantal, Balmer, Dirk, Hund, Andreas, Mauch-Mani, Brigitte
Title: A soil-free root observation system for the study of root-microorganism interactions in maize
Abstract: The root surface of a plant usually exceeds the leaf area and is constantly exposed to a variety of soil-borne microorganisms. Root pathogens and pests, as well as belowground interactions with beneficial microbes, can significantly influence a plants' performance. Unfortunately, the analysis of these interactions is often limited because of the arduous task of accessing roots growing in soil. Here, we present a soil-free root observation system (SF-ROBS) designed to grow maize (Zea mays) plants and to study root interactions with either beneficial or pathogenic microbes. The SF-ROBS consists of pouches lined with wet filter paper supplying nutrient solution. The aspect of maize grown in the SF-ROBS was similar to soil-grown maize; the plant growth was similar for the shoot but different for the roots (biomass and length increased in the SF-ROBS). SF-ROBS-grown roots were successfully inoculated with the hemi-biotrophic maize fungal pathogen Colletotrichum graminicola and the beneficial rhizobacteria Pseudomonas putida KT2440. Thus, the SF-ROBS is a system suitable to study two major belowground phenomena, namely root fungal defense reactions and interactions of roots with beneficial soil-borne bacteria. This system contributes to a better understanding of belowground plant microbe interactions in maize and most likely also in other crops.
Published in: Plant and Soil
Volume: 367
Issue: 1-2
Pages: 605 - 614
ISSN: 0032-079X, 1573-5036
Publication date / Date received: 2013-01-01
Publication status: Berlin
Publication status: Published
Subjects: Bodenkunde|Soil Science, Corn, Zea mays, Root infection, Pathogen, Rhizobacteria, Colletotrichum graminicola, Pseudomonas putida
Language: English
Review status: Peer reviewed
Keyword: Corn, Zea mays, Root infection, Pathogen, Rhizobacteria, Colletotrichum graminicola, Pseudomonas putida
DBID source: WOS-000319771700043, CSV-
DOI: 10.1007/s11104-012-1497-8
Nebis system number: 000052447
, Pinto, Francisco, Mielewczik, Michael, Liebisch, Frank, Walter, Achim, Greven, Hartmut, Rascher, Uwe, 2013 >>
Author(s): Pinto, Francisco, Mielewczik, Michael, Liebisch, Frank, Walter, Achim, Greven, Hartmut, Rascher, Uwe
Title: Non-Invasive Measurement of Frog Skin Reflectivity in High Spatial Resolution Using a Dual Hyperspectral Approach
Abstract: Background: Most spectral data for the amphibian integument are limited to the visible spectrum of light and have been collected using point measurements with low spatial resolution. In the present study a dual camera setup consisting of two push broom hyperspectral imaging systems was employed, which produces reflectance images between 400 and 2500 nm with high spectral and spatial resolution and a high dynamic range.
Methodology/Principal Findings: We briefly introduce the system and document the high efficiency of this technique analyzing exemplarily the spectral reflectivity of the integument of three arboreal anuran species (Litoria caerulea, Agalychnis callidryas and Hyla arborea), all of which appear green to the human eye. The imaging setup generates a high number of spectral bands within seconds and allows non-invasive characterization of spectral characteristics with relatively high working distance. Despite the comparatively uniform coloration, spectral reflectivity between 700 and 1100 nm differed markedly among the species. In contrast to H. arborea, L. caerulea and A. callidryas showed reflection in this range. For all three species, reflectivity above 1100 nm is primarily defined by water absorption. Furthermore, the high resolution allowed examining even small structures such as fingers and toes, which in A. callidryas showed an increased reflectivity in the near infrared part of the spectrum.
Conclusion/Significance: Hyperspectral imaging was found to be a very useful alternative technique combining the spectral resolution of spectrometric measurements with a higher spatial resolution. In addition, we used Digital Infrared/Red-Edge Photography as new simple method to roughly determine the near infrared reflectivity of frog specimens in field, where hyperspectral imaging is typically difficult.
Published in: PLoS ONE
Volume: 8
Issue: 9
Pages: e73234
ISSN: 1932-6203
Publication date / Date received: 2013-01-01
Publication status: Lawrence, Kan.
Publication status: Published
Language: English
DBID source: CSV-, SCOPUS-84884241815
DOI: 10.1371/journal.pone.0073234
Nebis system number: 006206116
, Peterhansel, C., Krause, K., Braun, H.P., Espie, G.S., Fernie, A.R., Hanson, D.T., Keech, O., Maurino, V.G., Mielewczik, M., Sage, R.F., 2013 >>
Author(s): Peterhansel, C., Krause, K., Braun, H.P., Espie, G.S., Fernie, A.R., Hanson, D.T., Keech, O., Maurino, V.G., Mielewczik, M., Sage, R.F.
Title: Engineering photorespiration
Subtitle: Current state and future possibilities
Abstract: Reduction of flux through photorespiration has been viewed as a major way to improve crop carbon fixation and yield since the energy-consuming reactions associated with this pathway were discovered. This view has been supported by the biomasses increases observed in model species that expressed artificial bypass reactions to photorespiration. Here, we present an overview about the major current attempts to reduce photorespiratory losses in crop species and provide suggestions for future research priorities.
Published in: Plant biology
Volume: 15
Issue: 4
Pages: 754 - 758
ISSN: 1435-8603, 1438-8677
Publication date / Date received: 2013-01-01
Publication status: Oxford
Publication status: Published
Language: English
DBID source: CSV-
DOI: 10.1111/j.1438-8677.2012.00681.x
Nebis system number: 002040196
, Mielewczik, Michael, Friedli, Michael, Kirchgessner, Norbert, Walter, Achim, 2013 >>
Author(s): Mielewczik, Michael, Friedli, Michael, Kirchgessner, Norbert, Walter, Achim
Title: Diel leaf growth of soybean
Subtitle: A novel method to analyze two-dimensional leaf expansion in high temporal resolution based on a marker tracking approach (Martrack Leaf)
Abstract: Background: We present a novel method for quantitative analysis of dicot leaf expansion at high temporal resolution. Image sequences of growing leaves were assessed using a marker tracking algorithm. An important feature of the method is the attachment of dark beads that serve as artificial landmarks to the leaf margin. The beads are mechanically constricted to the focal plane of a camera. Leaf expansion is approximated by the increase in area of the polygon defined by the centers of mass of the beads surrounding the leaf. Fluctuating illumination conditions often pose serious problems for tracking natural structures of a leaf; this problem is circumvented here by the use of the beads.

Results: The new method has been used to assess leaf growth in environmental situations with different illumination conditions that are typical in agricultural and biological experiments: Constant illumination via fluorescent light tubes in a climate chamber, a mix of natural and artificial illumination in a greenhouse and natural illumination of the situation on typical summer days in the field. Typical features of diel (24h) soybean leaf growth patterns were revealed in all three conditions, thereby demonstrating the general applicability of the method. Algorithms are provided to the entire community interested in using such approaches.

Conclusions: The implementation Martrack Leaf presented here is a robust method to investigate diel leaf growth rhythms both under natural and artificial illumination conditions. It will be beneficial for the further elucidation of genotype x environment x management interactions affecting leaf growth processes.
Published in: Plant methods
Volume: 9
Issue: 7
Pages: 30
ISSN: 1746-4811
Publication date / Date received: 2013-01-01
Publication status: London
Publication status: Published
Subjects: Botanik |Botany , Marker tracking, Phenotyping, Image analysis, Plant growth, Diel growth, Natural illumination
Language: English
Keyword: Marker tracking, Phenotyping, Image analysis, Plant growth, Diel growth, Natural illumination
DBID source: CSV-, WOS-000322990700001
DOI: 10.1186/1746-4811-9-30
Nebis system number: 005576870
, Liebisch, F., Keller, F., Huguenin-Elie, O., Frossard, E., Oberson, A., Bünemann, E.K., 2013 >>
Author(s): Liebisch, F., Keller, F., Huguenin-Elie, O., Frossard, E., Oberson, A., Bünemann, E.K.
Title: Seasonal dynamics and turnover of microbial phosphorusin a permanent grassland
Abstract: Microbial activity is known to be high under permanent grassland, but consequences for soil phosphorus (P) dynamics and availability are not well understood. Our main objective was to assess the microbial P turnover derived from the seasonal fluctuations in microbial P (measured as hexanol-labile P (Phex) at 13 sampling times during 9 months) in a permanent grassland in Switzerland as affected by different P fertilization treatments (P inputs of 0 (NK) or 17 kg P ha−1 year−1 in the form of superphosphate (NPK) or dairy slurry (DS)). Plant P uptake, available inorganic P measured as resin-extractable P (Pres), potential organic P mineralization indicated by acid phosphomonoesterase activity and climatic conditions were also recorded. Despite significant differences in plant P uptake and Pres (NPK > DS > NK), the turnover rate of Phex was similar in all treatments (approximately once per growing season). Thus, the seasonal P flux through Phex was similar to the stock of Phex, which was about 18, 25 and 37 kg P ha−1 in NK, NPK and DS, respectively, and larger than the corresponding seasonal plant P uptake of 6, 17 and 12 kg P ha−1. The estimate of Phex turnover based on seasonal dynamics did not confirm previous tracer-based findings of a much faster Phex turnover under low availability of inorganic P, and the magnitude of Phex turnover depended on the number of sampling points taken into account. Fluctuations in Pres and Phex were related to soil moisture and indicated competition between plants and microorganisms for available P.
Published in: Biology and fertility of soils
ISSN: 0178-2762, 1432-0789
Publication date / Date received: 2013-01-01
Publication status: Berlin
Publication status: Published
Subjects: Phosphorus, Microbial biomass, Turnover, Seasonal fluctuations, Permanent grassland
Language: English
Keyword: Phosphorus, Microbial biomass, Turnover, Seasonal fluctuations, Permanent grassland
DBID source: FORM-1386774662, WOS-000333022800005, SCOPUS-84897532613
DOI: 10.1007/s00374-013-0868-5
Nebis system number: 000031855
, Liebisch, F., Bünemann, E.K., Huguenin-Elie, O., Jeangros, B., Frossard, E., Oberson, A., 2013 >>
Author(s): Liebisch, F., Bünemann, E.K., Huguenin-Elie, O., Jeangros, B., Frossard, E., Oberson, A.
Title: Plant phosphorus nutrition indicators evaluated in agricultural grasslands managed at different intensities
Abstract: A precise assessment of the phosphorus (P) nutrition status of plants is necessary for an efficient P management inagriculturalgrasslands. Plant mineral analysis is a tool to identify the nutrition status of grasslands and several P indicators derived thereof are available. However, the interpretation of plant P indicatorsingrassland samples is complex due to variation in botanical composition, changing nutrient concentrations during growth and interactions between nutrients. The aim of this study was to compare indicators on the P nutrition status of plants and eventually to improve their application inagriculturalgrasslands. We studied three agriculturalgrassland types in Switzerland that were managedatdifferentintensity either for high biodiversity or high forage production. Each grassland type was for 5–25 years subjected to treatments of low, recommended or high rates of P, nitrogen (N) and potassium (K) fertilizer. The recommended P rates ranged from 15 to 48 kg P ha−1 year−1. We measured plant P, N and K concentrations in the aboveground biomass of grasses, legumes and forbs. The evaluated P indicators were: P concentration, N:P and K:P ratios and the P nutrition index (PNI). The PNI is calculated as P concentration divided by the linear relationship describing optimal sward P concentration as a function of N concentration (PNI = 100P/(0.06 × 5N + 1.5)). We observed significant yield reduction compared to the expected yield only when one or more nutrients were omitted from fertilization. Fertilizer P input higher than recommended did not significantly increase yields above the yield expected for the respective management and altitude. Under P limiting conditions, forbs and legumes had significantly higher P concentrations than grasses. Additionally, the proportion of legumes affected the P indicators integrating N. Therefore, we used the P indicatorsin the grass fraction, which was always the main botanical fraction. In grasses all P indicators differentiated between P fertilized and non-P-fertilized treatments. Concentrations of P from 2.1 to 3.0 mg g−1 indicated sufficient P supply, while yield was reduced at lower and not increased at higher concentrations, suggesting luxurious P consumption. Our results for N:P and K:P suggested optimal ranges of 5.5–9.0 and 6.0–10.5, respectively. The PNI showed a clear differentiation between deficient, sufficient or surplus fertilizer inputs. For the precise and correct interpretation of the plant P nutrition status inagriculturalgrasslands under different management, we propose to use the PNI in the grass fraction. Finally, the interpretation of the indicators was valid for the agriculturalgrasslandsmanagedatdifferentintensitiesin spite that the grass fraction was composed by different species.
Published in: European journal of agronomy
Volume: 44
Pages: 67 - 77
ISSN: 1161-0301
Publication date / Date received: 2013-01-01
Publication status: Amsterdam
Publication status: Published
Language: English
Review status: Peer reviewed
DBID source: FORM-1352298517, WOS-000311067000008
DOI: 10.1016/j.eja.2012.08.004
Nebis system number: 000650747
, Kautz, Timo, et al., Walter, Achim, 2013 >>
Author(s): Kautz, Timo, et al., Walter, Achim
Title: Nutrient acquisition from arable subsoils in temperate climates
Subtitle: A review
Abstract: In arable farming systems, the term ‘subsoil’ refers to the soil beneath the tilled or formerly tilled soil horizon whereas the latter one is denoted as ‘topsoil’. To date, most agronomic and plant nutrition studies have widely neglected subsoil processes involved in nutrient acquisition by crop roots. Based on our current knowledge it can be assumed that subsoil properties such as comparatively high bulk density, low air permeability, and poverty of organic matter, nutrients and microbial biomass are obviously adverse for nutrient acquisition, and sometimes subsoils provide as little as less than 10% of annual nutrient uptake in fertilised arable fields. Nevertheless, there is also strong evidence indicating that subsoil can contribute to more than two-thirds of the plant nutrition of N, P and K, especially when the topsoil is dry or nutrient-depleted. Based on the existing literature, nutrient acquisition from arable subsoils may be conceptualised into three major process components: (I) mobilisation from the subsoil, (II) translocation to the shoot and long-term accumulation in the Ap horizon and (III) re-allocation to the subsoil. The quantitative estimation of nutrient acquisition from the subsoil requires the linking of field experiments with mathematical modelling approaches on different spatial scales including Process Based Models for the field scale and Functional–Structural Plant Models for the plant scale. Possibilities to modify subsoil properties by means of agronomic management are limited, but ‘subsoiling’ – i.e. deep mechanical loosening – as well as the promotion of biopore formation are two potential strategies for increasing access to subsoil resources for crop roots in arable soils. The quantitative role of biopores in the nutrient acquisition from the subsoil is still unclear, and more research is needed to determine the bioaccessibility of nutrients in subsoil horizons.
Published in: Soil Biology and Biochemistry
Volume: 57
Pages: 1003 - 1022
ISSN: 0038-0717
Publication date / Date received: 2013-01-01
Publication status: Amsterdam
Publication status: Published
Subjects: Bodenkunde|Soil Science, Oekologie|Ecology, Structure dynamics, Biopore formation, Root growth, Drilosphere, Rhizodeposition, Microbial activity
Language: English
Review status: Peer reviewed
Keyword: Structure dynamics, Biopore formation, Root growth, Drilosphere, Rhizodeposition, Microbial activity
DBID source: FORM-1357751417
DOI: 10.1016/j.soilbio.2012.09.014
Nebis system number: 000036683
, Hersch, Nils, Wolters, Benjamin, Dreissen, Georg, Springer, Ronald, Kirchgeßner, Norbert, Merkel, Rudolf, Hoffmann, Bernd, 2013 >>
Author(s): Hersch, Nils, Wolters, Benjamin, Dreissen, Georg, Springer, Ronald, Kirchgeßner, Norbert, Merkel, Rudolf, Hoffmann, Bernd
Title: The constant beat
Subtitle: Cardiomyocytes adapt their forces by equal contraction upon environmental stiffening
Abstract: Cardiomyocytes are responsible for the permanent blood flow by coordinated heart contractions. This vital function is accomplished over a long period of time with almost the same performance, although heart properties, as its elasticity, change drastically upon aging or as a result of diseases like myocardial infarction. In this paper we have analyzed late rat embryonic heart muscle cells' morphology, sarcomere/costamere formation and force generation patterns on substrates of various elasticities ranging from ∼1 to 500 kPa, which covers physiological and pathological heart stiffnesses. Furthermore, adhesion behaviour, as well as single myofibril/sarcomere contraction patterns, was characterized with high spatial resolution in the range of physiological stiffnesses (15 kPa to 90 kPa). Here, sarcomere units generate an almost stable contraction of ∼4%. On stiffened substrates the contraction amplitude remains stable, which in turn leads to increased force levels allowing cells to adapt almost instantaneously to changing environmental stiffness. Furthermore, our data strongly indicate specific adhesion to flat substrates via both costameric and focal adhesions. The general appearance of the contractile and adhesion apparatus remains almost unaffected by substrate stiffness.
Published in: Biology open
Volume: 2
Issue: 3
Pages: 351
ISSN: 2046-6390
Publication date / Date received: 2013-01-01
Publication status: Cambridge
Publication status: Published
Subjects: Biologie allgemein|Biology, General, Cardiomyocyte, Traction force microscopy, Cell adhesion, Mechanoresponse, Myofibril, Sarcomere
Language: English
Keyword: Cardiomyocyte, Traction force microscopy, Cell adhesion, Mechanoresponse, Myofibril, Sarcomere
DBID source: CSV-
DOI: 10.1242/​bio.20133830
Nebis system number: 009788219
, Gebhard, Claude-Alain, Büchi, Lucie, Liebisch, Frank, Sinaj, Sokrat, Ramseier, Hans, Charles, Raphaël, 2013 >>
Author(s): Gebhard, Claude-Alain, Büchi, Lucie, Liebisch, Frank, Sinaj, Sokrat, Ramseier, Hans, Charles, Raphaël
Title: Beurteilung von Leguminosen als Gründüngungspflanzen
Subtitle: Stickstoff und Begleitflora
Abstract: In der vorliegenden Studie wurden 27 Leguminosen als Bodenbedeckungspflanzen in Rein- und Mischkultur beurteilt. Ziel war es, deren Nutzen in Agro-Ökosystemen zu ermitteln. Die Resultate zeigen grosse Unterschiede im Verhalten der verschiedenen geprüften Arten. Die gebildete oberirdische Biomasse für die Zeitspanne von August bis zum ersten Frost lag zwischen 0,4 und 5,9 Tonnen Trockensubstanz pro Hektare. Es sind 377 bis 850 Gradtage nötig, um eine Bodenbedeckung von 50 % zu erreichen. Der durch die Leguminosen akkumulierte Stickstoff stammt vorwiegend aus der symbiotischen Stickstoff-Fixierung und beläuft sich von wenigen Kilogrammen bis zu 150 kg N/ha in drei Wachstumsmonaten. Die Konkurrenzkraft der Leguminosen gegenüber der Begleitflora ist eng mit der Menge der erzeugten Biomasse korreliert (R2 = 0,93). Sie ist verwandt mit der Fähigkeit der geprüften Leguminosen Bestandesgemeinschaften in Mischung mit Phazelia und Hafer zu bilden. Fünf Arten (Saat-Platterbse, Ackerbohne, Erbse, Zottelwicke, Futterwicke) sind besonders dominant und machen 80 % der Biomasse in Mischung mit Phazelia aus, beziehungsweise etwa 70 % in Mischung mit Hafer. Diese fünf Arten sind jene, welche am meisten Biomasse erzeugen, den Boden am schnellsten bedecken und am meisten Luftstickstoff fixieren. Zahlreiche weitere Leguminosen (Schabzigerklee, Linse, weisse Lupine, Soja, Alexandrinerklee, Perserklee, Inkarnatklee, Ungarische Wicke) sind weniger konkurrenzfähig und eignen sich so gut zur Ergänzung von Pflanzengemeinschaften.
Published in: Agrarforschung Schweiz
Volume: 4
Issue: 9
Pages: 384 - 393
ISSN: 1663-7852, 1663-7909
Publication date / Date received: 2013-01-01
Publication status: Posieux
Publication status: Published
Subjects: Legumes, Cover crops, Biological nitrogen fixation, Weed control, Intercropping
Language: German
Keyword: Legumes, Cover crops, Biological nitrogen fixation, Weed control, Intercropping
DBID source: CSV-
Nebis system number: 005928960
, Walter, Achim, Studer, Bruno, Kölliker, Roland, 2012 >>
Author(s): Walter, Achim, Studer, Bruno, Kölliker, Roland
Title: Advanced phenotyping offers opportunities for improved breeding of forage and turf species
Abstract: Background and Aims: Advanced phenotyping, i.e. the application of automated, high-throughput methods to characterize plant architecture and performance, has the potential to accelerate breeding progress but is far from being routinely used in current breeding approaches. In forage and turf improvement programmes, in particular, where breeding populations and cultivars are characterized by high genetic diversity and substantial genotype × environment interactions, precise and efficient phenotyping is essential to meet future challenges imposed by climate change, growing demand and declining resources. Scope: This review highlights recent achievements in the establishment of phenotyping tools and platforms. Some of these tools have originally been established in remote sensing, some in precision agriculture, while others are laboratory-based imaging procedures. They quantify plant colour, spectral reflection, chlorophyll-fluorescence, temperature and other properties, from which traits such as biomass, architecture, photosynthetic efficiency, stomatal aperture or stress resistance can be derived. Applications of these methods in the context of forage and turf breeding are discussed. Conclusions: Progress in cutting-edge molecular breeding tools is beginning to be matched by progress in automated non-destructive imaging methods. Joint application of precise phenotyping machinery and molecular tools in optimized breeding schemes will improve forage and turf breeding in the near future and will thereby contribute to amended performance of managed grassland agroecosystems.
Published in: Annals of botany
Volume: 110
Issue: 6
Pages: 1271 - 1279
ISSN: 0305-7364, 0003-4754, 1095-8290
Publication date / Date received: 2012-01-01
Publication status: Oxford
Publication status: Published
Subjects: Forage, Turf, Breeding, Phenotyping, Growth, Biomass, Imaging, Marker-assisted selection, Remote sensing
Language: English
Review status: Peer reviewed
Keyword: Forage, Turf, Breeding, Phenotyping, Growth, Biomass, Imaging, Marker-assisted selection, Remote sensing
DBID source: FORM-1346071299, WOS-000310371800018
DOI: 10.1093/aob/mcs026
Nebis system number: 000033951
, Timm, Stefan, Mielewczik, Michael, Florian, Alexandra, Frankenbach, Silja, Dreissen, Anne, Hocken, Nadine, Fernie, Alisdair R., Walter, Achim, Bauwe, Hermann, 2012 >>
Author(s): Timm, Stefan, Mielewczik, Michael, Florian, Alexandra, Frankenbach, Silja, Dreissen, Anne, Hocken, Nadine, Fernie, Alisdair R., Walter, Achim, Bauwe, Hermann
Title: High-to-Low CO2 Acclimation Reveals Plasticity of the Photorespiratory Pathway and Indicates Regulatory Links to Cellular Metabolism of Arabidopsis
Abstract: Background: Photorespiratory carbon metabolism was long considered as an essentially closed and nonregulated pathway with little interaction to other metabolic routes except nitrogen metabolism and respiration. Most mutants of this pathway cannot survive in ambient air and require CO2-enriched air for normal growth. Several studies indicate that this CO2 requirement is very different for individual mutants, suggesting a higher plasticity and more interaction of photorespiratory metabolism as generally thought. To understand this better, we examined a variety of high- and low-level parameters at 1% CO2 and their alteration during acclimation of wild-type plants and selected photorespiratory mutants to ambient air. Methodology and Principal Findings: The wild type and four photorespiratory mutants of Arabidopsis thaliana (Arabidopsis) were grown to a defined stadium at 1% CO2 and then transferred to normal air (0.038% CO2). All other conditions remained unchanged. This approach allowed unbiased side-by-side monitoring of acclimation processes on several levels. For all lines, diel (24 h) leaf growth, photosynthetic gas exchange, and PSII fluorescence were monitored. Metabolite profiling was performed for the wild type and two mutants. During acclimation, considerable variation between the individual genotypes was detected in many of the examined parameters, which correlated with the position of the impaired reaction in the photorespiratory pathway. Conclusions: Photorespiratory carbon metabolism does not operate as a fully closed pathway. Acclimation from high to low CO2 was typically steady and consistent for a number of features over several days, but we also found unexpected short-term events, such as an intermittent very massive rise of glycine levels after transition of one particular mutant to ambient air. We conclude that photorespiration is possibly exposed to redox regulation beyond known substrate-level effects. Additionally, our data support the view that 2-phosphoglycolate could be a key regulator of photosynthetic-photorespiratory metabolism as a whole.
Published in: PLoS ONE
Volume: 7
Issue: 8
Pages: e42809
ISSN: 1932-6203
Publication date / Date received: 2012-01-01
Publication status: Published
Language: English
Review status: Peer reviewed
DBID source: FORM-1346075199, WOS-000308063700024
DOI: 10.1371/journal.pone.0042809
Nebis system number: 006206116
, Stamp, Peter, Messmer, Rainer, Walter, Achim, 2012 >>
Author(s): Stamp, Peter, Messmer, Rainer, Walter, Achim
Title: Competitive underutilized crops will depend on the state funding of breeding programmes
Subtitle: An opinion on the example of Europe
Abstract: Today, food security depends on very few major grain crops, actually an outcome of breeding success and globalization. This will not change in the near future. But action must be taken to stop the unprecedented pace of the erosion of biodiversity on arable fields; this is a prerequisite to ensure robust cropping systems as well as complementary food production for coming generations. Although this has been discussed for decades, little progress has been made. Most underutilized crops are no longer suitable for todays agriculture. Success can be achieved only by planning long-term breeding programmes instead of screening underutilized crops again and again. This cannot be realized, however, by market-driven private breeders. State funding is mandatory to launch a programme of a set of well-chosen crops. Guidelines are provided, based on case examples from cool temperate regions, where promising crops undergo stepwise selection process. In Europe, a programme could be established in the frame of a virtual institute, wisely investing a small part of the direct payments that go to farmers today, thereby safeguarding their future.
Published in: Plant Breeding
Volume: 131
Issue: 4
Pages: 461 - 464
ISSN: 0179-9541, 1439-0523
Publication date / Date received: 2012-01-01
Publication status: Berlin
Publication status: Published
Subjects: Acker- und Futterbau (inkl. Kultur- und Nutzpflanzen) | Crop and Fodder Farming (incl. Cultivated and Crop Plants), Underutilized crops, Alternative crops, Long-term breeding
Language: English
Review status: Peer reviewed
Keyword: Underutilized crops, Alternative crops, Long-term breeding
DBID source: WOS-000306406900001, FORM-1357808167
DOI: 10.1111/j.1439-0523.2012.01990.x
Nebis system number: 000034603
, Ruts, Tom, Matsubara, Shizue, Wiese-Klinkenberg, Anika, Walter, Achim, 2012 >>
Author(s): Ruts, Tom, Matsubara, Shizue, Wiese-Klinkenberg, Anika, Walter, Achim
Title: Diel patterns of leaf and root growth
Subtitle: Endogenous rhythmicity or environmental response?
Abstract: Plants are sessile organisms forced to adjust to their surrounding environment. In a single plant the photoautotrophic shoot is exposed to pronounced environmental variations recurring in a day-night 24 h (diel) cycle, whereas the heterotrophic root grows in a temporally less fluctuating environment. The contrasting habitats of shoots and roots are reflected in different diel growth patterns and their responsiveness to environmental stimuli. Differences between diel leaf growth patterns of mono- and dicotyledonous plants correspond to their different organization and placement of growth zones. In monocots, heterotrophic growth zones are organized linearly and protected from the environment by sheaths of older leaves. In contrast, photosynthetically active growth zones of dicot leaves are exposed directly to the environment and show characteristic, species-specific diel growth patterns. It is hypothesized that the different exposure to environmental constraints and simultaneously the sink/source status of the growing organs may have induced distinct endogenous control of diel growth patterns in roots and leaves of monocot and dicot plants. Confronted by strong temporal fluctuations in environment, the circadian clock may facilitate robust intrinsic control of leaf growth in dicot plants.
Published in: Journal of experimental botany
Volume: 63
Issue: 9
Pages: 3339 - 3351
ISSN: 0022-0957, 1460-2431
Publication date / Date received: 2012-01-01
Publication status: Oxford
Publication status: Published
Subjects: Botanik |Botany , Carbohydrate, Circadian, Dicot, Diurnal, Environment, Growth, Leaf, Monocot, Regulation, Root
Language: English
Review status: Peer reviewed
Keyword: Carbohydrate, Circadian, Dicot, Diurnal, Environment, Growth, Leaf, Monocot, Regulation, Root
DBID source: WOS-000304836300003, FORM-1346071867
DOI: 10.1093/jxb/err334
Nebis system number: 000049325
, Ruts, Tom, Matsubara, Shizue, Wiese-Klinkenberg, Anika, Walter, Achim, 2012 >>
Author(s): Ruts, Tom, Matsubara, Shizue, Wiese-Klinkenberg, Anika, Walter, Achim
Title: Aberrant temporal growth pattern and morphology of root and shoot caused by a defective circadian clock in Arabidopsis thaliana
Abstract: Circadian clocks synchronized with the environment allow plants to anticipate recurring daily changes and give a fitness advantage. Here, we mapped the dynamic growth phenotype of leaves and roots in two lines of Arabidopsis thaliana with a disrupted circadian clock: the CCA1 over-expressing line (CCA1ox) and the prr9 prr7 prr5 (prr975) mutant. We demonstrate leaf growth defects due to a disrupted circadian clock over a 24 h time scale. Both lines showed enhanced leaf growth compared with the wild-type during the diurnal period, suggesting increased partitioning of photosynthates for leaf growth. Nocturnal leaf growth was reduced and growth inhibition occurred by dawn, which may be explained by ineffective starch degradation in the leaves of the mutants. However, this growth inhibition was not caused by starch exhaustion. Overall, these results are consistent with the notion that the defective clock affects carbon and energy allocation, thereby reducing growth capacity during the night. Furthermore, rosette morphology and size as well as root architecture were strikingly altered by the defective clock control. Separate analysis of the primary root and lateral roots revealed strong suppression of lateral root formation in both CCA1ox and prr975, accompanied by unusual changes in lateral root growth direction under lightdark cycles and increased lateral extension of the root system. We conclude that growth of the whole plant is severely affected by improper clock regulation in A. thaliana, resulting not only in altered timing and capacity for growth but also aberrant development of shoot and root architecture.
Published in: The plant journal
Volume: 72
Issue: 1
Pages: 154 - 161
ISSN: 0960-7412, 1365-313X
Publication date / Date received: 2012-01-01
Publication status: Oxford
Publication status: Published
Subjects: Botanik |Botany , Circadian clock, Growth, Leaf, Root, Starch, Arabidopsis thaliana
Language: English
Review status: Peer reviewed
Keyword: Circadian clock, Growth, Leaf, Root, Starch, Arabidopsis thaliana
DBID source: WOS-000309064100013
DOI: 10.1111/j.1365-313X.2012.05073.x
Nebis system number: 000600719
, Rosar, Christian, Kanonenberg, Kerstin, Nanda, Arun M., Mielewczik, Michael, Bräutigam, Andrea, Novak, Ondrej, Strnad, Miroslav, Walter, Achim, Weber, Andreas P.M., 2012 >>
Author(s): Rosar, Christian, Kanonenberg, Kerstin, Nanda, Arun M., Mielewczik, Michael, Bräutigam, Andrea, Novak, Ondrej, Strnad, Miroslav, Walter, Achim, Weber, Andreas P.M.
Title: The Leaf Reticulate Mutant dov1 Is Impaired in the First Step of Purine Metabolism
Abstract: A series of reticulated Arabidopsis thaliana mutants were previously described. All mutants show a reticulate leaf pattern, namely green veins on a pale leaf lamina. They have an aberrant mesophyll structure but an intact layer of bundle sheath cells around the veins. Here, we unravel the function of the previously described reticulated EMS-mutant dov1 (differential development of vascular associated cells 1). By positional cloning, we identified the mutated gene, which encodes glutamine phosphoribosyl pyrophosphate aminotransferase 2 (ATase2), an enzyme catalyzing the first step of purine nucleotide biosynthesis. dov1 is allelic to the previously characterized cia1-2 mutant that was isolated in a screen for mutants with impaired chloroplast protein import. We show that purine-derived total cytokinins are lowered in dov1 and crosses with phytohormone reporter lines revealed differential reporter activity patterns in dov1. Metabolite profiling unraveled that amino acids that are involved in purine biosynthesis are increased in dov1. This study identified the molecular basis of an established mutant line, which has the potential for further investigation of the interaction between metabolism and leaf development.
Published in: Molecular plant
Volume: 5
Issue: 6
Pages: 1227 - 1241
ISSN: 1674-2052, 1752-9867
Publication date / Date received: 2012-01-01
Publication status: Oxford
Publication status: Published
Subjects: Botanik |Botany
Language: English
Review status: Peer reviewed
DBID source: FORM-1346072310
DOI: 10.1093/mp/sss045
Nebis system number: 005962904
, Niediek, Verena, Born, Simone, Hampe, Nico, Kirchgeßner, Norbert, Merkel, Rudolf, Hoffmann, Bernd, 2012 >>
Author(s): Niediek, Verena, Born, Simone, Hampe, Nico, Kirchgeßner, Norbert, Merkel, Rudolf, Hoffmann, Bernd
Title: Cyclic stretch induces reorientation of cells in a Src family kinase-and p130Cas-dependent manner
Abstract: Recognition of external mechanical signals by cells is an essential process for life. One important mechanical signal experienced by various cell types, e.g. around blood vessels, within the lung epithelia or around the intestine, is cyclic stretch. As a response, many cell types reorient their actin cytoskeleton and main cell axis almost perpendicular to the direction of stretch. Despite the vital necessity of cellular adaptation to cyclic stretch, the underlying mechanosensory signal cascades are far from being understood. Here we show an important function of Src-family kinase activity in cellular reorientation upon cyclic stretch. Deletion of all three family members, namely c-Src, Yes and Fyn (SYF), results in a strongly impaired cell reorientation of mouse embryonic fibroblasts with an only incomplete reorientation upon expression of c-Src. We further demonstrate that this reorientation phenotype of SYF-depleted cells is not caused by affected protein exchange dynamics within focal adhesions or altered cell force generation. Instead, Src-family kinases regulate the reorientation in a mechanotransduction-dependent manner, since knock-down and knock-out of p130Cas, a putative stretch sensor known to be phosphorylated by Src-family kinases, also reduce cellular reorientation upon cyclic stretch. This impaired reorientation is identical in intensity upon mutating stretch-sensitive tyrosines of p130Cas only. These statistically highly significant data pinpoint early events in a Src family kinase- and p130Cas-dependent mechanosensory/mechanotransduction pathway.
Published in: European journal of cell biology : EJCB
Volume: 91
Issue: 2
Pages: 118 - 128
ISSN: 0171-9335
Publication date / Date received: 2012-01-01
Publication status: Jena
Publication status: Published
Subjects: Biochemie, Molekularbiologie und Zellbiologie|Biochemistry, Molecular Biology and Cell Biology, p130Cas, c-Src, Fyn, Yes, Cyclic stretch, Cell reorientation, Tyrosine phosphorylation, Mechanotransduction
Language: English
Keyword: p130Cas, c-Src, Fyn, Yes, Cyclic stretch, Cell reorientation, Tyrosine phosphorylation, Mechanotransduction
DBID source: CSV-
DOI: 10.1016/j.ejcb.2011.10.003
Nebis system number: 000986113
, Möhl, Christoph, Kirchgessner, Norbert, Schäfer, Claudia, Hoffman, Bernd, Merkel, Rudolf, 2012 >>
Author(s): Möhl, Christoph, Kirchgessner, Norbert, Schäfer, Claudia, Hoffman, Bernd, Merkel, Rudolf
Title: Quantitative mapping of averaged focal adhesion dynamics in migrating cells by shape normalization
Abstract: The spatially ordered formation and disassembly of focal adhesions is a basic requirement for effective cell locomotion. Because focal adhesions couple the contractile actin–myosin network to the substrate, their distribution determines the pattern of traction forces propelling the cell in a certain direction. In the present study, we quantitatively analyzed the spatial patterning of cell–substrate adhesion in migrating cells by mapping averaged focal adhesion growth dynamics to a standardized cell coordinate system. These maps revealed distinct zones of focal adhesion assembly, disassembly and stability and were strongly interrelated with corresponding actin flow and traction force patterns. Moreover, the mapping technique enables precise detection of even minute responses of adhesion dynamics upon targeted signaling perturbations. For example, the partial inhibition of vinculin phosphorylation was followed by the reduced number of newly formed adhesions, whereas growth dynamics of existing adhesions remained unaffected.
Published in: Journal of cell science
Volume: 125
Issue: 1
Pages: 155 - 165
ISSN: 0021-9533, 1477-9137
Publication date / Date received: 2012-01-01
Publication status: Cambridge
Publication status: Published
Subjects: Biochemie, Molekularbiologie und Zellbiologie|Biochemistry, Molecular Biology and Cell Biology, Actin flow, Cell migration, Focal adhesion dynamics, Traction force
Language: English
Keyword: Actin flow, Cell migration, Focal adhesion dynamics, Traction force
DBID source: FORM-1357806900, WOS-000300329100015
DOI: 10.1242/jcs.090746
Nebis system number: 000977877
, Kjaer, Kathrine Heinsvig, Poiré, Richard, Ottosen, Carl-Otto, Walter, Achim, 2012 >>
Author(s): Kjaer, Kathrine Heinsvig, Poiré, Richard, Ottosen, Carl-Otto, Walter, Achim
Title: Rapid adjustment in chrysanthemum carbohydrate turnover and growth activity to a change in time-of-day application of light and daylength
Abstract: Diel (24 h) rhythms are believed to be of great importance to plant growth and carbohydrate metabolism in fluctuating environments. However, it is unclear how plants that have evolved to experience regular day–night patterns will respond to irregular light environments that disturb diurnally-regulated parameters related to growth. In this study, chrysanthemum plants were exposed to a change in the time-of-day application of light followed by short days or long days with a night interruption of light. We observed a clear shift in the diel cycle of sucrose turnover and relative leaf expansion, indicating a resetting of these activities with a temporal trigger in the early morning. The starch pool was relatively stable in long-day plants and marginally affected by the change in the time-of-day application in light followed by long days with a night interruption. This was in contrast with an onset of a daily starch turnover by a shift to short days. These results confirm findings from model species on the complex relationship between carbohydrate metabolism, source–sink relations and growth rate and they shed new light on the dynamic processes during acclimation towards altered environmental responses of plants in fluctuating environments.
Published in: Functional plant biology
Volume: 39
Issue: 8
Pages: 639 - 649
ISSN: 1445-4408
Publication date / Date received: 2012-01-01
Publication status: Collingwood
Publication status: Published
Subjects: Botanik |Botany , Diurnal regulation, Carbohydrate metabolism, Photosynthesis, Sugar sensing
Language: English
Keyword: Diurnal regulation, Carbohydrate metabolism, Photosynthesis, Sugar sensing
DBID source: FORM-1357806472, WOS-000307520200002
DOI: 10.1071/FP11289
Nebis system number: 004240289
, Hund, Andreas, Reimer, Regina, Stamp, Peter, Walter, Achim, 2012 >>
Author(s): Hund, Andreas, Reimer, Regina, Stamp, Peter, Walter, Achim
Title: Can we improve heterosis for root growth of maize by selecting parental inbred lines with different temperature behaviour?
Abstract: Tolerance to high and low temperature is an important breeding aim for Central and Northern Europe, where temperature fluctuations are predicted to increase. However, the extent to which genotypes differ in their response to the whole range of possible temperatures is not well understood. We tested the hypothesis that the combination of maize (Zea mays L.) inbred lines with differing temperature optima for root growth would lead to superior hybrids. This hypothesis is based on the concept of 'marginal overdominance' in which the hybrid expresses higher relative fitness than its parents, summed over all situations. The elongation rates of axile and lateral roots of the reciprocal cross between two flint and two dent inbred lines were assessed at temperatures between 15 degrees C and 40 degrees C. Indeed, the cross between UH005 and UH250 with lateral root growth temperature optima at 34 degrees C and 28 degrees C, respectively, resulted in intermediate hybrids. At temperatures below and above 31 degrees C, the hybrids' root growth was comparable to the better parent, respectively, thereby increasing temperature tolerance of the hybrid compared with its parents. The implications of and reasons for this heterosis effect are discussed in the context of breeding for abiotic stress tolerance and of putatively underlying molecular mechanisms. This finding paves the way for more detailed investigations of this phenomenon in future studies.
Published in: Philosophical transactions of the Royal Society. B, Biological sciences
Volume: 367
Issue: 1595
Pages: 1580 - 1588
ISSN: 0962-8436, 1471-2970
Publication date / Date received: 2012-01-01
Publication status: London
Publication status: Published
Subjects: Flint, Dent, Corn, Marginal overdominance, Root, Abiotic stress
Language: English
Review status: Peer reviewed
Keyword: Flint, Dent, Corn, Marginal overdominance, Root, Abiotic stress
DBID source: WOS-000303107900016, FORM-1357750584
DOI: 10.1098/rstb.2011.0242
Nebis system number: 000558205
, Babé, Aurélie, Lavigne, Tristan, Séverin, Jean-Philippe, Nagel, Kerstin A., Walter, Achim, Chaumont, François, Batoko, Henri, Beeckman, Tom, Draye, Xavier, 2012 >>
Author(s): Babé, Aurélie, Lavigne, Tristan, Séverin, Jean-Philippe, Nagel, Kerstin A., Walter, Achim, Chaumont, François, Batoko, Henri, Beeckman, Tom, Draye, Xavier
Title: Repression of early lateral root initiation events by transient water deficit in barley and maize
Abstract: The formation of lateral roots (LRs) is a key driver of root system architecture and developmental plasticity. The first stage of LR formation, which leads to the acquisition of founder cell identity in the pericycle, is the primary determinant of root branching patterns. The fact that initiation events occur asynchronously in a very small number of cells inside the parent root has been a major difficulty in the study of the molecular regulation of branching patterns. Inducible systems that trigger synchronous lateral formation at predictable sites have proven extremely valuable in Arabidopsis to decipher the first steps of LR formation. Here, we present a LR repression system for cereals that relies on a transient water-deficit treatment, which blocks LR initiation before the first formative divisions. Using a time-lapse approach, we analysed the dynamics of this repression along growing roots and were able to show that it targets a very narrow developmental window of the initiation process. Interestingly, the repression can be exploited to obtain negative control root samples where LR initiation is absent. This system could be instrumental in the analysis of the molecular basis of drought-responsive as well as intrinsic pathways of LR formation in cereals.
Published in: Philosophical transactions of the Royal Society. B, Biological sciences
Volume: 367
Issue: 1595
Pages: 1534 - 1541
ISSN: 0962-8436, 1471-2970
Publication date / Date received: 2012-01-01
Publication status: London
Publication status: Published
Subjects: Biologie allgemein|Biology, General, Lateral root initiation, Water deficit, Barley, Maize
Language: English
Review status: Peer reviewed
Keyword: Lateral root initiation, Water deficit, Barley, Maize
DBID source: FORM-1346074696
DOI: 10.1098/rstb.2011.0240
Nebis system number: 000558205
, Rupitak, Quanjai, Stamp, Peter, Jampatong, Sansern, Chowchong, Surapol, Messmer, Rainer, 2011 >>
Author(s): Rupitak, Quanjai, Stamp, Peter, Jampatong, Sansern, Chowchong, Surapol, Messmer, Rainer
Title: Temporal dynamics of kernel set of tropical sweet maize (Zea mays L.) as influenced by genotype and mild drought
Abstract: Maize grain yield is often affected by drought stress at flowering. Fast and synchronous emergence of silks probably is the key to high kernel set but non-destructive methods to follow the temporal grain set were missing. We solved this problem by marking flint kernels on the ears of sweet maize to reflect daily kernel set, as modern sweet maize is quite similar in vigor to field maize in Thailand. The effects of mild pre-anthesis drought stress and of the genotype were examined in two experiments (over two years both). The highest number of kernels resulted from pollination on the first or second day of silking. More than 90% of the kernels per ear were usually set by day four or five. Mild drought stress reduced the number of kernel-bearing positions along the ear as well as the number of kernels per position on each day of pollination in 2007 but there was no significant deviation in the principal grain set curve. As a consequence of mild drought stress, the differences in daily kernel set between the two water regimes were rather small compared to the differences among genotypes, for which genotype-specific deviations from the general pattern of daily kernel set were observed. Most important, a new tool exists now to reliably study variable stress situations, using normal grains on sweet maize ears or yellow grains on white grain ears as visual marker systems.
Published in: Maydica
Volume: 56
Issue: 1
Pages: 25 - 31
ISSN: 0025-6153
Publication date / Date received: 2011-01-01
Publication status: Bergamo
Publication status: Published
Subjects: Sweet maize, Flowering dynamics, Kernel set, Visual markers, Drought stress
Language: English
Review status: Peer reviewed
Keyword: Sweet maize, Flowering dynamics, Kernel set, Visual markers, Drought stress
DBID source: FORM-1318931780, WOS-000300601400005
Nebis system number: 003931813
, Pitann, Britta, Kranz, Thorsten, Zörbb, Christian, Walter, Achim, Schurr, Ulrich, Mühling, Karl H., 2011 >>
Author(s): Pitann, Britta, Kranz, Thorsten, Zörbb, Christian, Walter, Achim, Schurr, Ulrich, Mühling, Karl H.
Title: Apoplastic pH and growth in expanding leaves of Vicia faba under salinity
Abstract: Salinity affects water availability in the soil and subsequently the plant uptake capacity. Upon exposure to salt stress, leaf growth in monocot plants has been shown to be reduced instantaneously, followed by a gradual acclimation. The growth reactions are caused by an initial water deficit and an accompanied osmotic effect, followed by an IAA-induced sequestration of protons into the apoplast that increases leaf growth again as explained by the acid growth theory. In this study, we investigated the dynamics of growth reactions and apoplastic pH in leaves of the dicot Vicia faba in the presence of NaCl during the initiation of salt stress. Concurrent changes in apoplastic pH were detected by ratiometric fluorescence microscopy using the fluorescent dye fluorescein tetramethylrhodamine dextran. To elucidate the possible relation between the dynamics of leaf growth and apoplastic pH, results of the ratio imaging technique were combined with an in vivo growth analysis imaging approach. Leaf growth rate of V. faba was highest in the dusk and the early night phase; at this time a concomitant decrease of the apoplastic pH was observed. Under salinity, the apoplastic pH in leaves of V. faba increased with a simultaneous decrease of leaf growth towards increasing developmental stages, but with complex aberrations in the 24-h-leaf-growth pattern compared to control leaves. In conclusion, these results show that salt stress leads to an increase in apoplastic pH and to a declined leaf growth activity with complex 24-h-interactions of growth and pH in V. faba.
Published in: Environmental and experimental botany
Volume: 74
Pages: 31 - 36
ISSN: 0098-8472
Publication date / Date received: 2011-01-01
Publication status: Amsterdam
Publication status: Published
Subjects: Apoplastic pH, Image analysis, Plant growth, Ratio imaging, Salinity, Vicia faba
Language: English
Review status: Peer reviewed
Keyword: Apoplastic pH, Image analysis, Plant growth, Ratio imaging, Salinity, Vicia faba
DBID source: FORM-1319465694
DOI: 10.1016/j.envexpbot.2011.04.015
Nebis system number: 000013717
, Messmer, Rainer, Fracheboud, Yvan, Bänziger, Marianne, Stamp, Peter, Ribaut, Jean-Marcel, 2011 >>
Author(s): Messmer, Rainer, Fracheboud, Yvan, Bänziger, Marianne, Stamp, Peter, Ribaut, Jean-Marcel
Title: Drought stress and tropical maize
Subtitle: QTLs for leaf greenness, plant senescence, and root capacitance
Abstract: Genetically improved crops with higher water productivity help maintaining and increasing agricultural production in drought-prone areas. Their development involves, as in the case of maize, selection for high grain yield and improved secondary traits. With the objective of better understanding the role and regulation of the morphology of drought adaptation, a recombinant inbred line (RIL) population of tropical maize (Zea mays L.) was evaluated in six field experiments under intermediate (IS) and severe (SS) drought stress at flowering and under well-watered (WW) conditions in Mexico. The analyses per water regime revealed 32 quantitative trait loci (QTLs) for the five measurements of relative content of leaf chlorophyll (CL), 25 for the five visual ratings of plant senescence (SEN), and 11 for the three measurements of electric root capacitance (RCT). Impressive clusters of QTLs were observed on chromosomes 2 (bins 2.03-05), 4 (bin 4.09), and 10 (bins 10.04-05), suggesting that a small number of genes control chlorophyll metabolism and plant senescence. The high CL and low SEN of the drought resistant parent are aspects of its high water productivity resulting from improved constitutive traits. Co-locations of QTLs for CL, SEN and RCT with QTLs for plant height (PHT), the anthesis-silking interval (ASI), and grain yield (GY) were observed in bins 1.06-07, 8.06, and 4.09 but not for the large QTL clusters on chromosomes 2 and 10, suggesting independent genetic control of reproductive traits. Still, the phenotypic data showed that high CL and low SEN were favorable for grain yield production under drought, while delayed SEN was associated with higher grain yield under WW conditions. CL and SEN are suitable to complement selection for drought tolerance in order to sustain future breeding progress.
Published in: Field crops research
Volume: 124
Issue: 1
Pages: 93 - 103
ISSN: 0378-4290
Publication date / Date received: 2011-01-01
Publication status: Amsterdam
Publication status: Published
Subjects: Maize, QTL, Drought stress, Leaf chlorophyll content, Senescence, Stay-green
Language: English
Review status: Peer reviewed
Keyword: Maize, QTL, Drought stress, Leaf chlorophyll content, Senescence, Stay-green
DBID source: FORM-1318931431, WOS-000296595800010
DOI: 10.1016/j.fcr.2011.06.010
Nebis system number: 000002745
, Hund, Andreas, Reimer, Regina, Messmer, Rainer, 2011 >>
Author(s): Hund, Andreas, Reimer, Regina, Messmer, Rainer
Title: A consensus map of QTLs controlling the root length of maize
Abstract: Traits related to the root length of maize (Zea mays L.), reported by 15 QTL studies of nine mapping populations, were subjected to a QTL meta-analysis. Traits were grouped according to ontology, and we propose a system of abbreviations to unambiguously identify the different root types and branching orders. The nine maps were merged into a consensus map, and the number and positions of putative QTL clusters (MQTLs) were determined. A total of 161 QTLs was grouped into 24 MQTLs and 16 individual QTLs. Seven MQTLs harbored root traits, which had been reported to be collocated with QTLs for grain yield or other drought-responsive traits in the field. The most consistent collocations were observed for the number and weight of the seminal roots (five loci). Based on our analysis at least six loci are good candidates for further evaluation (bins 1.07, 2.04, 2.08, 3.06, 6.05 and 7.04). For example, the MQTL in bin 2.04 harbored ten different single QTLs; the MQTLs in bins 1.07 and 3.06 combined 11 and 7 QTLs, respectively, that were detected in more than three populations. The presented database is a first step for a comprehensive overview of the genetic architecture of root system architecture and its ecophysiological function.
Published in: Plant and soil
Volume: 344
Issue: 1-2
Pages: 143 - 158
ISSN: 0032-079X, 1573-5036
Publication date / Date received: 2011-01-01
Publication status: Berlin
Publication status: Published
Subjects: Consensus map, Meta-analysis, QTL, Roots, Root system architecture, Zea mays L.
Language: English
Review status: Peer reviewed
Keyword: Consensus map, Meta-analysis, QTL, Roots, Root system architecture, Zea mays L.
DBID source: WOS-000291654600008
DOI: 10.1007/s11104-011-0735-9
Nebis system number: 000052447
, Walter, Achim, Behn, H., Tittmann, S., Schurr, U., Noga, G., Ulbrich, A., 2010 >>
Author(s): Walter, Achim, Behn, H., Tittmann, S., Schurr, U., Noga, G., Ulbrich, A.
Title: UV-B Transmittance of Greenhouse Covering Materials Affects Growth and Flavonoid Content of Lettuce Seedlings
Abstract: In Europe, lettuce ( Lactuca sativa L., Asteraceae ) is commonly raised in greenhouses and transplanted to the field at the age of two to four weeks in order to prolong the growing season. The sudden exposure to outdoor conditions including altered temperature, radiation levels and rainfall events is extremely stressful for non-acclimated seedlings. Particularly the increase in ultraviolet-B radiation is considered a serious threat. A new approach to pre-acclimate seedlings to ambient ultraviolet-B radiation is the use of ultraviolet-B transparent covering materials. In order to estimate the benefit of UV-B pre-acclimation, lettuce plants were raised in greenhouses covered with three different materials varying in ultraviolet-B transmittance and transplanted to the field at the age of three weeks. Ultraviolet-B exposure during the greenhouse period led to a reduction in growth (leaf length, leaf area and leaf number) and an increase in flavonoid content. Transplantation to the field induced a strong enhancement in flavonoid content and a severe growth reduction overriding differences between UV-B treatment groups within a few days. At the time of harvest plant fresh weight was therefore independent from previous ultraviolet-B treatment. Effects of UV-B acclimation on plant performance immediately after transplantation require more detailed examination.
Published in: European journal of horticultural science
Volume: 75
Issue: 6
Pages: 259 - 268
ISSN: 1611-4426, 1611-4434
Publication date / Date received: 2010-01-01
Publication status: Stuttgart
Publication status: Published
Subjects: Landwirtschaft allgemein|Agriculture, General, Lactuca sativa, Biomass, Flavonoids, Leaf area, Leaf length, Lettuce, UV-B radiation
Language: English
Review status: Peer reviewed
Keyword: Lactuca sativa, Biomass, Flavonoids, Leaf area, Leaf length, Lettuce, UV-B radiation
DBID source: FORM-1319457405
Nebis system number: 004491026
, Hund, Andreas, 2010 >>
Author(s): Hund, Andreas
Title: Genetic variation in the gravitropic response of maize roots to low temperatures
Abstract: The distribution of roots in soil determines their acquisition of spatially varying resources. It may be altered by changing the response of roots to gravity. The aim of the study was to assess gravitropic set-point angles (GSAs) of maize (Zea mays L.) roots, their response to temperature and the feasibility to measure them in growth pouches. The GSAs of the primary, seminal and crown roots of a set of nine temperate inbred lines were measured. The lines were grown under controlled conditions in growth columns either at 15/13°C or 24/20°C (day/night) until the two-leaf stage (V2). The GSA was measured as the deviation of the initial 3 cm of root axis from the vertical zero. Low temperature resulted in a decrease in the GSAs of the crown roots by 10°, i.e. the roots oriented more vertically. The effect of the GSAs on the distribution of the roots was verified in wider columns using two extreme inbred lines. The proportion of roots in the upper 5 cm of the columns was 78% for the line S335 with the strongest tendency to horizontal root growth and only 39% for CM105 with almost vertical orientation of the roots. The differences in GSAs between these two genotypes were even more pronounced in growth pouches, thus proving the feasibility of this system for rapid screening. The results indicate that there is a huge genetic variability available to alter the growth direction of the seedling roots of maize. However, there was little effect of the temperature.
Published in: Plant root
Volume: 4
Pages: 22 - 30
ISSN: 1881-6754
Publication date / Date received: 2010-01-01
Publication status: Tokyo
Publication status: Published
Subjects: Corn, Gravitropism, Liminal angle, Plagio-gravitropism, Root angle, Zea mays L.
Language: English
Review status: Peer reviewed
Keyword: Corn, Gravitropism, Liminal angle, Plagio-gravitropism, Root angle, Zea mays L.
DBID source: FORM-1318491947
DOI: 10.3117/plantroot.4.22
, Achim Walter, 2010 >>
Author(s): Achim Walter
Title: UV-B Transmittance of Greenhouse Covering Materials Affects Growth and Flavonoid Content of Lettuce Seedlings
Publication date / Date received: 2010-01-01
Language: English
DBID source: FORM-1319457643
, Hund, A., Trachsel, S., Stamp, P., 2009 >>
Author(s): Hund, A., Trachsel, S., Stamp, P.
Title: Growth of axile and lateral roots of maize
Subtitle: I development of a phenotying platform
Abstract: The objective of this study was to develop a phenotyping platform for the non-destructive, digital measurement of early root growth of axile and lateral roots and to evaluate its suitability for identifying maize (Zea mays L.) genotypes with contrasting root development. The system was designed to capture images of the root system within minutes and to batch process them automatically. For system establishment, roots of the inbred line Ac7729/TZSRW were grown until nine days after germination on the surface of a blotting paper in pouches. An A4 scanner was used for image acquisition followed by digital image analysis. Image processing was optimized to enhance the separation between the roots and the background and to remove image noise. Based on the root length in diameter-class distribution (RLDD), small-diameter lateral roots and large-diameter axile roots were separated. Root systems were scanned daily to model the growth dynamics of these root types. While the axile roots exhibited an almost linear growth, total lateral root length increased exponentially. Given the determined exponential growth, it was demonstrated that two plants, germinated one day apart but with the same growth rates differed in root length by 100%. From the growth rates we were able to identify contrasting genotypes from 236 recombinant inbred lines (RILs) of the CML444 x SC-Malawi cross. Differences in the growth of lateral roots of two selected RILs were due to differences in the final length and linear density of the primary lateral roots, as proven by the manual reanalysis of the digital images. The high throughput makes the phenotyping platform attractive for routine genetic studies and other screening purposes.
Published in: Plant and soil
Volume: 325
Issue: 1-2
Pages: 335 - 349
ISSN: 0032-079X, 1573-5036
Publication date / Date received: 2009-01-01
Publication status: Berlin
Publication status: Published
Subjects: Landwirtschaft allgemein|Agriculture, General, Digital image analysis, Corn, Early vigor, Root growth, Root morphology, Seedling vigor, Zea mays L
Language: English
Review status: Peer reviewed
Keyword: Digital image analysis, Corn, Early vigor, Root growth, Root morphology, Seedling vigor, Zea mays L
DBID source: PP-53737, WOS-000272383900028
DOI: 10.1007/s11104-009-9984-2
Nebis system number: 000052447

 

 

 

Group of Agronomy and Plant Breeding

Prof. Dr. Peter Stamp, emeritus.

[expand all]

 

, Sinkangam, Bunyarit, Stamp, Peter, Srinives, Peerasak, Jompuk, Peeranuch, Mongkol, Wassamon, Porniyom, Angkana, Dang, Ngoc-Chi, Jompuk, Choosak, 2011 >>
Author(s): Sinkangam, Bunyarit, Stamp, Peter, Srinives, Peerasak, Jompuk, Peeranuch, Mongkol, Wassamon, Porniyom, Angkana, Dang, Ngoc-Chi, Jompuk, Choosak
Title: Integration of Quality Protein in Waxy Maize by Means of Simple Sequence Repeat Markers
Abstract: Waxy, that is, pure, amylopectin maize (Zea mays L.) is an important staple food and vegetable in Southeast and East Asia. Its insufficient protein quality could be remedied by the opaque-2 gene mutation, demanding the combination of two recessive endosperm quality genes, opaque-2 (o(2)o(2)) and waxy (wxwx). Crosses were made between waxy and opaque-2 maize as female and male parents, respectively. In the segregating progenies of two crosses, Kwi1 x AgQ53 and Kwi9 x AgQ53, immediate selfing or one-time backcrossing to the waxy parent before selfing were used to achieve the combination o(2)o(2) wxwx, supported by marker-assisted selection (MAS) of opaque-2 by phi057 and of waxy by phi022. The final 11 o(2)o(2) wxwx lines were achieved both from initial backcrossing and selfing. All the o(2)o(2) wxwx lines were of acceptable agronomic vigor and had very high percentages of amylopectin. The sugar content was mostly higher in both selfing and backcrossing lines than in the parental waxy lines, an advantage for vegetable marketing. High lysine and tryptophan contents of the o(2)o(2) wxwx lines prove that the goal of combining two quality traits within one grain was achieved. Furthermore, high variation in grain quality traits is an incentive for further improvement by breeding. Consumption of high-quality protein maize will improve the diets of children, a good reason to produce double-quality vegetable waxy maize.
Published in: Crop science
Volume: 51
Issue: 6
Pages: 2499 - 2504
ISSN: 0011-183X
Publication date / Date received: 2011-01-01
Publication status: Madison, WI
Publication status: Published
Subjects: Landwirtschaft allgemein|Agriculture, General
Language: English
Review status: Peer reviewed
DBID source: WOS-000295839200020
DOI: 10.2135/cropsci2011.05.0271
Nebis system number: 000036710
, Sangakkara, U.R., Amarasekera, P., Stamp, P., 2011 >>
Author(s): Sangakkara, U.R., Amarasekera, P., Stamp, P.
Title: Root development, shoot growth and yields of maize as affected by irrigation schedules in a minor season in tropical Asia
Abstract: Maize is the most important upland cereal in tropical Asia, grown in both major and minor seasons under rainfed conditions. Due to the inadequate rainfall in the minor season, the crop is subjected to water stress, and irrigation helps to produce high yields. Smallholders who grow maize on flat beds in their allotments often use surface flood irrigation whenever irrigation water is available, which leads in most instances to inefficient use of this valuable resource. A field study was carried out over two minor seasons in Sri Lanka to determine the impact of different schedules of irrigation, developed on the basis of time intervals (3-, 7-, 14- or 21-day intervals or no irrigation as a control), which can easily be practised by smallholders, on the root development, shoot growth, seed yield and water use efficiency of maize. Irrigation at 3-day intervals produced fine roots in the top layers of the soil. Increasing the time interval between irrigation schedules to 7, 14 or 21 days reduced the percentage of fine roots, but developed more, heavier roots in the lower soil layers, as determined by root length densities (RLD) and root weight densities (RWD). Longer irrigation intervals or lack of irrigation resulted in a smaller number of heavier roots in the soil profile. The leaf water potential was affected to a greater degree than shoot water content or relative water content. The seed yield and harvest index were highest when maize was irrigated at 7-day intervals. In contrast, irrigation water use efficiency (IWUE) was highest at an irrigation interval of 14 days. The potential for optimizing water use in surface irrigation in flat beds while obtaining high yields in a tropical Asian minor season, when maize is subjected to moisture stress under smallholding conditions, is presented on the basis of this study.
Published in: Acta Agronomica Hungarica
Volume: 59
Issue: 2
Pages: 149 - 158
ISSN: 0238-0161, 1588-2527
Publication date / Date received: 2011-01-01
Publication status: Budapest
Publication status: Published
Subjects: Maize, Irrigation, Root growth, Shoots, Water use efficiency, Yield
Language: English
Review status: Peer reviewed
Keyword: Maize, Irrigation, Root growth, Shoots, Water use efficiency, Yield
DBID source: FORM-1318930349
DOI: 10.1556/AAgr.59.2011.2.5
, Sangakkara, Ravi, Amarasekera, Prasanna, Stamp, Peter, 2011 >>
Author(s): Sangakkara, Ravi, Amarasekera, Prasanna, Stamp, Peter
Title: Growth, Yields, and Nitrogen-Use Efficiency of Maize (Zea mays L.) and Mungbean (Vigna radiata L. Wilczek) as Affected by Potassium Fertilizer in Tropical South Asia
Abstract: Application of chemical fertilizers in smallholder tropical farming systems of South Asia has become mandatory because of soil degradation, and nitrogen (N) is the most abundantly used nutrient. However, integrated management of N with potassium (K) could enhance productivity. Field studies tested the impact of fertilizer K on root development, seed yields, harvest indices, and N-use efficiencies of maize and mungbean, two popular smallholder crops over major and minor seasons. Application of 120 kg K ha-1 optimized all parameters of maize in the major wet season, whereas the requirement was 80 kg K ha-1 in the minor season. Optimal growth yields and N-use efficiencies of mungbean was with 80 kg K ha-1 in both seasons. Information regarding rates of fertilizer K that optimized N use and yield of maize and mungbean during each of the two tropical monsoonal seasons of South Asia is presented.
Published in: Communications in soil science and plant analysis
Volume: 42
Issue: 7
Pages: 832 - 843
ISSN: 0010-3624, 1532-2416
Publication date / Date received: 2011-01-01
Publication status: Philadelphia, PA
Publication status: Published
Subjects: Landwirtschaft allgemein|Agriculture, General, Cropping seasons, maize, mungbean, nitrogen, potassium, tropics
Language: English
Review status: Peer reviewed
Keyword: Cropping seasons, maize, mungbean, nitrogen, potassium, tropics
DBID source: WOS-000288950000007
DOI: 10.1080/00103624.2011.552663
Nebis system number: 000036687
, Rupitak, Quanjai, Stamp, Peter, Jampatong, Sansern, Chowchong, Surapol, Messmer, Rainer, 2011 >>
Author(s): Rupitak, Quanjai, Stamp, Peter, Jampatong, Sansern, Chowchong, Surapol, Messmer, Rainer
Title: Temporal dynamics of kernel set of tropical sweet maize (Zea mays L.) as influenced by genotype and mild drought
Abstract: Maize grain yield is often affected by drought stress at flowering. Fast and synchronous emergence of silks probably is the key to high kernel set but non-destructive methods to follow the temporal grain set were missing. We solved this problem by marking flint kernels on the ears of sweet maize to reflect daily kernel set, as modern sweet maize is quite similar in vigor to field maize in Thailand. The effects of mild pre-anthesis drought stress and of the genotype were examined in two experiments (over two years both). The highest number of kernels resulted from pollination on the first or second day of silking. More than 90% of the kernels per ear were usually set by day four or five. Mild drought stress reduced the number of kernel-bearing positions along the ear as well as the number of kernels per position on each day of pollination in 2007 but there was no significant deviation in the principal grain set curve. As a consequence of mild drought stress, the differences in daily kernel set between the two water regimes were rather small compared to the differences among genotypes, for which genotype-specific deviations from the general pattern of daily kernel set were observed. Most important, a new tool exists now to reliably study variable stress situations, using normal grains on sweet maize ears or yellow grains on white grain ears as visual marker systems.
Published in: Maydica
Volume: 56
Issue: 1
Pages: 25 - 31
ISSN: 0025-6153
Publication date / Date received: 2011-01-01
Publication status: Bergamo
Publication status: Published
Subjects: Sweet maize, Flowering dynamics, Kernel set, Visual markers, Drought stress
Language: English
Review status: Peer reviewed
Keyword: Sweet maize, Flowering dynamics, Kernel set, Visual markers, Drought stress
DBID source: FORM-1318931780, WOS-000300601400005
Nebis system number: 003931813
, Messmer, Rainer, Fracheboud, Yvan, Bänziger, Marianne, Stamp, Peter, Ribaut, Jean-Marcel, 2011 >>
Author(s): Messmer, Rainer, Fracheboud, Yvan, Bänziger, Marianne, Stamp, Peter, Ribaut, Jean-Marcel
Title: Drought stress and tropical maize
Subtitle: QTLs for leaf greenness, plant senescence, and root capacitance
Abstract: Genetically improved crops with higher water productivity help maintaining and increasing agricultural production in drought-prone areas. Their development involves, as in the case of maize, selection for high grain yield and improved secondary traits. With the objective of better understanding the role and regulation of the morphology of drought adaptation, a recombinant inbred line (RIL) population of tropical maize (Zea mays L.) was evaluated in six field experiments under intermediate (IS) and severe (SS) drought stress at flowering and under well-watered (WW) conditions in Mexico. The analyses per water regime revealed 32 quantitative trait loci (QTLs) for the five measurements of relative content of leaf chlorophyll (CL), 25 for the five visual ratings of plant senescence (SEN), and 11 for the three measurements of electric root capacitance (RCT). Impressive clusters of QTLs were observed on chromosomes 2 (bins 2.03-05), 4 (bin 4.09), and 10 (bins 10.04-05), suggesting that a small number of genes control chlorophyll metabolism and plant senescence. The high CL and low SEN of the drought resistant parent are aspects of its high water productivity resulting from improved constitutive traits. Co-locations of QTLs for CL, SEN and RCT with QTLs for plant height (PHT), the anthesis-silking interval (ASI), and grain yield (GY) were observed in bins 1.06-07, 8.06, and 4.09 but not for the large QTL clusters on chromosomes 2 and 10, suggesting independent genetic control of reproductive traits. Still, the phenotypic data showed that high CL and low SEN were favorable for grain yield production under drought, while delayed SEN was associated with higher grain yield under WW conditions. CL and SEN are suitable to complement selection for drought tolerance in order to sustain future breeding progress.
Published in: Field crops research
Volume: 124
Issue: 1
Pages: 93 - 103
ISSN: 0378-4290
Publication date / Date received: 2011-01-01
Publication status: Amsterdam
Publication status: Published
Subjects: Maize, QTL, Drought stress, Leaf chlorophyll content, Senescence, Stay-green
Language: English
Review status: Peer reviewed
Keyword: Maize, QTL, Drought stress, Leaf chlorophyll content, Senescence, Stay-green
DBID source: FORM-1318931431, WOS-000296595800010
DOI: 10.1016/j.fcr.2011.06.010
Nebis system number: 000002745
, Kohls, Susanne, Stamp, Peter, Knaak, Carsten, Messmer, Rainer, 2011 >>
Author(s): Kohls, Susanne, Stamp, Peter, Knaak, Carsten, Messmer, Rainer
Title: QTL involved in the partial restoration of male fertility of C-type cytoplasmic male sterility in maize
Abstract: Partial restoration of male fertility limits the use of C-type cytoplasmic male sterility (C-CMS) for the production of hybrid seeds in maize. Nevertheless, the genetic basis of the trait is still unknown. Therefore, the aim to this study was to identify genomic regions that govern partial restoration by means of a QTL analysis carried out in an F-2 population (n = 180). This population was derived from the Corn Belt inbred lines B37C and K55. F2BC1 progenies were phenotyped at three locations in Switzerland. Male fertility was rated according to the quality and number of anthers as well as the anthesis-silking interval. A weak effect of environment on the expression of partial restoration was reflected by high heritabilities of all fertility-related traits. Partial restoration was inherited like an oligogenic trait. Three major QTL regions were found consistently across environments in the chromosomal bins 2.09, 3.06 and 7.03. Therefore, a marker-assisted counter-selection of partial restoration is promising. Minor QTL regions were found on chromosomes 3, 4, 5, 6 and 8. A combination of partial restorer alleles at different QTL can lead to full restoration of fertility. The maternal parent was clearly involved in the partial restoration, because the restorer alleles at QTL in bins 2.09, 6.04 and 7.03 originated from B37. The three major QTL regions collocated with other restorer genes of maize, a phenomenon, which seems to be typical for restorer genes. Therefore, a study of the clusters of restorer genes in maize could lead to a better understanding of their evolution and function. In this respect, the long arm of chromosome 2 is particularly interesting, because it harbors restorer genes for the three major CMS systems (C, T and S) of maize.
Published in: Theoretical and applied genetics
Volume: 123
Issue: 2
Pages: 327 - 338
ISSN: 0040-5752, 1432-2242
Publication date / Date received: 2011-01-01
Publication status: Berlin
Publication status: Published
Language: English
Review status: Peer reviewed
DBID source: WOS-000291600800011
DOI: 10.1007/s00122-011-1586-8
Nebis system number: 000985869
, Hund, Andreas, Reimer, Regina, Messmer, Rainer, 2011 >>
Author(s): Hund, Andreas, Reimer, Regina, Messmer, Rainer
Title: A consensus map of QTLs controlling the root length of maize
Abstract: Traits related to the root length of maize (Zea mays L.), reported by 15 QTL studies of nine mapping populations, were subjected to a QTL meta-analysis. Traits were grouped according to ontology, and we propose a system of abbreviations to unambiguously identify the different root types and branching orders. The nine maps were merged into a consensus map, and the number and positions of putative QTL clusters (MQTLs) were determined. A total of 161 QTLs was grouped into 24 MQTLs and 16 individual QTLs. Seven MQTLs harbored root traits, which had been reported to be collocated with QTLs for grain yield or other drought-responsive traits in the field. The most consistent collocations were observed for the number and weight of the seminal roots (five loci). Based on our analysis at least six loci are good candidates for further evaluation (bins 1.07, 2.04, 2.08, 3.06, 6.05 and 7.04). For example, the MQTL in bin 2.04 harbored ten different single QTLs; the MQTLs in bins 1.07 and 3.06 combined 11 and 7 QTLs, respectively, that were detected in more than three populations. The presented database is a first step for a comprehensive overview of the genetic architecture of root system architecture and its ecophysiological function.
Published in: Plant and soil
Volume: 344
Issue: 1-2
Pages: 143 - 158
ISSN: 0032-079X, 1573-5036
Publication date / Date received: 2011-01-01
Publication status: Berlin
Publication status: Published
Subjects: Consensus map, Meta-analysis, QTL, Roots, Root system architecture, Zea mays L.
Language: English
Review status: Peer reviewed
Keyword: Consensus map, Meta-analysis, QTL, Roots, Root system architecture, Zea mays L.
DBID source: WOS-000291654600008
DOI: 10.1007/s11104-011-0735-9
Nebis system number: 000052447
, Egodawatte, W.C.P., Sangakkara, U.R., Wijesinghe, D.B., Stamp, P., 2011 >>
Author(s): Egodawatte, W.C.P., Sangakkara, U.R., Wijesinghe, D.B., Stamp, P.
Title: Impact of Green Manure on Productivity Patterns of Homegardens and Fields in a Tropical Dry Climate
Abstract: Extensive field farming and homegardening (representing an intensive resource management system) on different inclination positions were compared on the basis of soil quality and productivity of maize and Mung bean over two years, in Meegahakiula, Sri Lanka. Soil organic matter (SOM) content of homegardens was greater than in fields irrespective of the inclination and it was more pronounced in the flat category. After two years, SOM declined in both homegardens and fields, the depletion of SOM was greater in homegardens, due to a positive correlation between SOM depletion rate and crop yields. Green manures moderated SOM depletion. Mean maize yields in homegardens with recommended fertilizers (NPK) exceeded 5 Mg.ha-1 and was significantly different from Fields in both Flat and Moderate categories. No yield difference was observed in homegardens and Fields in the Steep category. Although mineral fertilizers had an overriding effect over green manures, plots without fertilizers (ZERO and G) had higher yields in homegardens. Mungbean yield was similar in homegardens and Fields with recommended fertilizers (NPK) in Flat category, in both years. However, the difference became significant with increasing inclination. The influence of green manure was overridden by the influence of mineral fertilizers while no difference was observed between homegardens and Fields without mineral fertilizers (ZERO). The study illustrated that homegardens as an intensive resource management system is more fertile and productive than the extensive field farming and more effective in terms of long term sustainability.
Published in: Tropical agricultural research
Volume: 22
Issue: 2
Pages: 172 - 182
ISSN: 1016-1422
Publication date / Date received: 2011-01-01
Publication status: Peradeniya, Sri Lanka
Publication status: Published
Subjects: Green manure, Homegardens, Intensive resource management system, Sustainability
Language: English
Review status: Peer reviewed
Keyword: Green manure, Homegardens, Intensive resource management system, Sustainability
DBID source: FORM-1318930591
DOI: 10.4038/tar.v22i2.2826
Nebis system number: 004911578
, Dietiker, Dominique, Stamp, Peter, Eugster, Werner, 2011 >>
Author(s): Dietiker, Dominique, Stamp, Peter, Eugster, Werner
Title: Predicting seed admixture in maize combining flowering characteristics and a Lagrangian stochastic dispersion model
Abstract: The seed purity problem has received very low attention in maize coexistence studies, and has not been considered in prediction tools that simulate pollen flow and out-crossing between maize fields. To fill this gap we developed the Seed Admixture Model (SAMETH) able to predict seed admixture dispersion combining flowering characteristics (pollen shed, silks exertion) with a Lagrangian stochastic dispersion model. The model was tested with a dataset obtained from 20 fields in 2007 and in 2008, whose seeds were mixed with 1% of a homozygous blue-kernelled hybrid. The model was first calibrated with data from 6 fields and then validated with the data from the remaining 14 fields. Moreover, a sensitivity analysis was performed to test the consequences of different pollen quantities released by the admixture and the commercial hybrids. The measured seed admixture ranged from 0.7% to 6% and the model was able to simulate the seed admixture with r(2) = 0.83. The sensitivity analysis showed that the model was sensitive to the absolute released pollen quantities but it was still able to predict seed admixture rather accurately. Because of its reliability, the model could become a useful tool for case study scenarios that involve seed admixture and for which field implementations would be too complex and time-consuming. (C) 2010 Elsevier B.V. All rights reserved.
Published in: Field crops research
Volume: 121
Issue: 2
Pages: 256 - 267
ISSN: 0378-4290
Publication date / Date received: 2011-01-01
Publication status: Amsterdam
Publication status: Published
Subjects: Seed purity, Admixture, Lagrangian stochastic model, Coexistence, Maize
Language: English
Review status: Peer reviewed
Keyword: Seed purity, Admixture, Lagrangian stochastic model, Coexistence, Maize
DBID source: WOS-000288473900007
DOI: 10.1016/j.fcr.2010.12.009
Nebis system number: 000002745
, Dietiker, Dominique, Oehen, Bernadette, Ochsenbein, Christian, Westgate, Mark E., Stamp, Peter, 2011 >>
Author(s): Dietiker, Dominique, Oehen, Bernadette, Ochsenbein, Christian, Westgate, Mark E., Stamp, Peter
Title: Field Simulation of Transgenic Seed Admixture Dispersion in Maize with a Blue Kernel Color Marker
Abstract: Seed purity in maize (Zea mays L.) has been almost neglected in coexistence studies. In this study, the impact of initial seed admixture was assessed in 20 fields (17 integrated pest management [IPM] and three organics) in the Swiss Midlands in 2007 and 2008 and a seed admixture threshold was proposed. The blue-kernelled French hybrid Adonis was used as a color-marker admixture. In 2009, its pollen production was assessed relative to those of two commercial hybrids (LG 32.12 and DKC 2960) that released 41 and 62%, respectively, less pollen than Adonis. Adonis was added to commercial yellow hybrid seeds at a proportion of 1:99. On average, the seed admixture at harvest was 2.8 times greater than the seed admixture at sowing. The greater pollen production of Adonis relative to yellow hybrids explained the increase in the harvest seed admixture via pollen flow. The lesser average kernel number per plant of Adonis (316 kernels plant−1; 451 kernels plant−1 for commercial hybrids) buffered the effect of pollen flow. Correcting for these differences provided simulation results compatible with the Hardy–Weinberg equilibrium for a trait with 1% frequency. When compared among the 20 field situations, (i) flower synchrony between admixture and commercial subpopulation and (ii) vertical distance between tassels of Adonis and ears of the commercial hybrid contributed most to field differences. To guarantee the 0.9% threshold imposed by the European Union for non-genetically-modified product, the seed admixture threshold should range between 0.2 and 0.5%.
Published in: Crop science
Volume: 51
Issue: 2
Pages: 829 - 837
ISSN: 0011-183X
Publication date / Date received: 2011-01-01
Publication status: Madison, WI
Publication status: Published
Language: English
Review status: Peer reviewed
DBID source: FORM-1318928773
DOI: 10.2135/cropsci2010.06.0311
Nebis system number: 000036710
, Dang, N. C., Munsch, M., Aulinger I., Renlai, W., Le-Huy, H., Jampatong, S., Stamp, P., 2011 >>
Author(s): Dang, N. C., Munsch, M., Aulinger I., Renlai, W., Le-Huy, H., Jampatong, S., Stamp, P.
Title: Composition of Starch and Protein in the Endosperm of Newly Generated Double Recessive Waxy and Opaque 2 Maize (Zea mays L.) Genotypes
Abstract: Waxy maize with its pure amylopectin starch is the staple food of many ethnic minorities in hilly regions of Southeast Asia (SEA). A combination of waxy and quality protein maize (QPM) traits would improve the quality of protein of waxy maize for human consumption. Double recessive waxy-QPM (wx-o2) genotypes had been generated from Southern Chinese material by haploid induction of crosses heterozygous for the two quality traits with an absolutely conserved waxy type and an improved amino acid profile. The vitreous kernel trait (due to the additional modifier genes present in QPM) was lost in the wx-o2 plant material; this may be due to the waxy mutation, this is anyhow desirable for acceptance as waxy maize is preferred due to its soft grains. The content of the quality limiting amino acid lysine was greatly increased in double recessive wx-o2 genotypes compared to standard waxy maize, but still with a high variation among genotypes for future improvement. Conclusively, it was indeed possible to combine two grain quality mutations successfully within one genotype and prototypes of double quality wx-o2 are available now to contribute to meet human requirements in essential amino acids and thus reduce malnutrition in various regions of Asia
Published in: Journal of Agricultural Science and Technology
Volume: 1
Issue: 5B
Pages: 631 - 637
ISSN: 2161-6256, 2161-6264
Publication date / Date received: 2011-01-01
Publication status: Libertyville
Publication status: Published
Subjects: Quality protein maize, GBSS I granule-bound starch synthase I, waxy maize
Language: English
Review status: Peer Reviewed
Keyword: Quality protein maize, GBSS I granule-bound starch synthase I, waxy maize
DBID source: FORM-1321272551
, Vogler, André, Bertossa, Mario, Aulinger-Leipner, Ingrid, Stamp, Peter, 2010 >>
Author(s): Vogler, André, Bertossa, Mario, Aulinger-Leipner, Ingrid, Stamp, Peter
Title: Weather effects on cross-pollination in maize
Abstract: Control of pollen dispersal is critical for the successful coexistence of genetically modified (GM) maize (Zea mays L.) and conventional maize. The impact of climate on cross-pollination by GM pollen was simulated in two field experiments with a color-recessive white-grain receptor DSP17007 and a color-dominant yellow-grain pollen donor in 2005 and 2006. The day after silk exertion of about 2500 marked single plants was taken as the basis for comparing weather data (maximum and minimum temperatures, relative humidity, wind speed, and average wind direction) with data on the cross-pollination of the white-grain receptor. Scattered significant correlations were found for all weather factors; only the minimum temperature at night had consistent negative correlations with rates of cross-pollination ranging from r = -0.22 to -0.45, indicating that the latter decreased as temperatures at night increased. In previous complementary field and growth chamber experiments, the grain set on one inbred line correlated significantly negatively with temperature up to 24 h before pollination (r = -0.55 to -0.66) because of pollen agglutination. This affects medium-distance pollen dispersals to a greater extent than short-distance ones; thus, cross-pollination with GM maize may be lower when the pollen donor has a proclivity for pollen agglutination at a high minimum temperature at night.
Published in: Crop science
Volume: 50
Issue: 2
Pages: 713 - 717
ISSN: 0011-183X
Publication date / Date received: 2010-01-01
Publication status: Madison, WI
Publication status: Published
Language: English
Review status: Peer reviewed
DBID source: WOS-000275564500031
DOI: 10.2135/cropsci2009.04.0213
Nebis system number: 000036710
, Trachsel, S., Messmer, R., Stamp, P., Ruta, N., Hund, A., 2010 >>
Author(s): Trachsel, S., Messmer, R., Stamp, P., Ruta, N., Hund, A.
Title: QTLs for early vigor of tropical maize
Abstract: A strong photosynthetic performance and rapid leaf development, are important indicators of vigorous early growth. The aim of this study was to (1) evaluate the tropical maize (Zea mays L.) inbred lines CML444 and SC-Malawi for their photosynthetic performance at different growth stages and (2) assess quantitative trait loci (QTL) of photosynthesis-related traits in their 236 recombinant inbred lines at the heterotrophic growth stage. CML444 had a higher leaf chlorophyll (SPAD) content than SC-Malawi. Ten QTLs were found for the quantum efficiency of photosystem II (I broken vertical bar(PSII); four), SPAD (three) and the specific leaf area (SLA; three). The relevance of seedling QTLs for I broken vertical bar(PSII), SPAD and SLA for yield formation is emphasized by seven collocations (bins 5.01, 7.03, 8.05) with QTLs for kernel number and grain yield under field conditions. QTLs for SPAD at the V2 and at the reproductive stage did not collocate, indicating differences in the genetic control of SPAD at different growth stages. Knowing which loci affect SLA, SPAD and I broken vertical bar(PSII) simultaneously and which do not will help to optimize light harvest by the canopy.
Published in: Molecular breeding
Volume: 25
Issue: 1
Pages: 91 - 103
ISSN: 1380-3743, 1380-3743
Publication date / Date received: 2010-01-01
Publication status: Berlin
Publication status: Published
Subjects: Wirtschaft, Recht und Politik allgemein|Economics, Law and Politics, General, QTL, Early vigor, Photosynthesis, Leaf chlorophyll content, SPAD, Zea mays L.
Language: English
Review status: Peer reviewed
Keyword: QTL, Early vigor, Photosynthesis, Leaf chlorophyll content, SPAD, Zea mays L.
DBID source: WOS-000273034800007
DOI: 10.1007/s11032-009-9310-y
Nebis system number: 001430119
, Sangakkara, U.R., Amarasekera, P., Stamp, P., 2010 >>
Author(s): Sangakkara, U.R., Amarasekera, P., Stamp, P.
Title: Irrigation regimes affect early root development, shoot growth and yields of maize (Zea mays L.) in tropical minor seasons
Abstract: Moisture stress is an important factor affecting field-grown maize in the tropics, especially in the minor dry seasons, and irrigation is required for successful crop growth and yields. Field experiments evaluated the impact of four irrigation regimes ranging from 3 to 21-day intervals on growth of maize (Zea mays L.) roots and shoots at critical stages and on seed yields when compared to those of irrigated maize plants in two minor seasons at Sri Lanka. While surface wetting at planting induced germination in all treatments, growth of seminal and first-order lateral roots was enhanced by increasing irrigation intervals. Relative water contents were similar at irrigation intervals of 3, 7 and 14 days and declined thereafter. At anthesis, root length and weight densities indicated the greater penetration into soil layers with increasing intervals of water supply. The highest yields were at 7 and 14-day irrigation intervals thus illustrating that regular water supply in minor dry seasons may be detrimental for maize growth and yields.
Published in: Plant, soil and environment
Volume: 56
Issue: 5
Pages: 228 - 234
ISSN: 1214-1178
Publication date / Date received: 2010-01-01
Publication status: Prague
Publication status: Published
Subjects: Landwirtschaft allgemein|Agriculture, General, Umweltproblematik allgemein|Environmental Problems, General, maize, minor seasons, tropics, irrigation, root initiation, development, yields
Language: English
Review status: Peer reviewed
Keyword: maize, minor seasons, tropics, irrigation, root initiation, development, yields
DBID source: WOS-000278035700004
Nebis system number: 004524506
, Ruta, Nathinee, Stamp, Peter, Liedgens, Markus, Fracheboud, Yvan, Hund, Andreas, 2010 >>
Author(s): Ruta, Nathinee, Stamp, Peter, Liedgens, Markus, Fracheboud, Yvan, Hund, Andreas
Title: Collocations of QTLs for Seedling Traits and Yield Components of Tropical Maize under Water Stress Conditions
Abstract: Genetic variation in root morphology and its response to water deficit might be crucial for the adaptation of maize (Zea mays L.) to drought, but information about this is scarce. A set of 208 recombinant inbred lines (RILs) from the cross between Ac7643 (Parent 1) and Ac7729/TZSRW (Parent 2) was investigated in growth pouches to determine the traits of seedling roots and shoots. Water stress was induced by polyethylene glycol (PEG 8000). Quantitative trait loci (QTLs) were identified for seedling traits at the first leaf stage; their collocation was compared with published yield-related traits found in drought-stress experiments. Some seedling QTLs were specific to water stress, such as QTLs for root dry weight, shoot dry weight, and leaf area-to-root length ratio. Four root and shoot QTLs collocated in bin 2.02, indicating a relationship of this chromosome region to early vigor under water stress. Quantitative trait loci for ear number collocated with QTLs for the shoot-to-root dry weight ratio and leaf area-to-root length ratio Quantitative trait loci for the anthesis-silking interval collocated with QTLs for the numbers of crown roots and seminal roots irrespective of water supply. Quantitative trait loci controlling the balance between early root and shoot development may provide useful information to enable the prediction of maize performance under field conditions.
Published in: Crop science
Volume: 50
Issue: 4
Pages: 1385 - 1392
ISSN: 0011-183X
Publication date / Date received: 2010-01-01
Publication status: Madison, WI
Publication status: Published
Language: English
Review status: Peer reviewed
DBID source: WOS-000279138200031
DOI: 10.2135/cropsci2009.01.0036
Nebis system number: 000036710
, Ruta, N., Liedgens, M., Fracheboud, Y., Stamp, Peter, Hund, A., 2010 >>
Author(s): Ruta, N., Liedgens, M., Fracheboud, Y., Stamp, Peter, Hund, A.
Title: QTLs for the elongation of axile and lateral roots of maize in response to low water potential
Abstract: Changes in root architecture and the maintenance of root growth in drying soil are key traits for the adaptation of maize (Zea mays L.) to drought environments. The goal of this study was to map quantitative trait loci (QTLs) for root growth and its response to dehydration in a population of 208 recombinant inbred lines from the International Maize and Wheat Improvement Center (CIMMYT). The parents, Ac7643 and Ac7729/TZSRW, are known to be drought-tolerant and drought-sensitive, respectively. Roots were grown in pouches under well-watered conditions or at low water potential induced by the osmolyte polyethylene glycol (PEG 8000). Axile root length (L (Ax)) increased linearly, while lateral root length (L (Lat)) increased exponentially over time. Thirteen QTLs were identified for six seedling traits: elongation rates of axile roots (ERAx), the rate constant of lateral root elongation (k (Lat)), the final respective lengths (L (Ax) and L (Lat)), and the ratios k (Lat)/ERAx and L (Lat)/L (Ax.) While QTLs for lateral root traits were constitutively expressed, most QTLs for axile root traits responded to water stress. For axile roots, common QTLs existed for ERAx and L (Ax). Quantitative trait loci for the elongation rates of axile roots responded more clearly to water stress compared to root length. Two major QTLs were detected: a QTL for general vigor in bin 2.02, affecting most of the traits, and a QTL for the constitutive increase in k (Lat) and k (Lat)/ERAx in bins 6.04-6.05. The latter co-located with a major QTL for the anthesis-silking interval (ASI) reported in published field experiments, suggesting an involvement of root morphology in drought tolerance. Rapid seedling tests are feasible for elucidating the genetic response of root growth to low water potential. Some loci may even have pleiotropic effects on yield-related traits under drought stress.
Published in: Theoretical and applied genetics
Volume: 120
Issue: 3
Pages: 621 - 631
ISSN: 0040-5752, 1432-2242
Publication date / Date received: 2010-01-01
Publication status: Berlin
Publication status: Published
Subjects: Drought, QTL, Root growth, Water potential, Drought resistance, Zea mays L., Corn
Language: English
Review status: Peer reviewed
Keyword: Drought, QTL, Root growth, Water potential, Drought resistance, Zea mays L., Corn
DBID source: WOS-000273755200011
DOI: 10.1007/s00122-009-1180-5
Nebis system number: 000985869
, Rupitak, Quanjai, Stamp, Peter, Jampatong, Sansern, Chowchong, Surapol, Messmer, Rainer, 2010 >>
Author(s): Rupitak, Quanjai, Stamp, Peter, Jampatong, Sansern, Chowchong, Surapol, Messmer, Rainer
Title: The temporal dynamics of kernel set in tropical sweet maize determined by visual markers
Abstract: The initiation of kernels along the maize ear depends on the temporal dynamics of silk emergence and pollen shedding. We conducted a nondestructive examination of the dynamics of silk emergence of tropical sweet maize (Zea mays L.); flint-type grains were the visual markers. The silks were pollinated on consecutive days with pollen of sweet maize (recessive allele) on 6 d and with pollen of flint-type maize (dominant allele) on 1 d (one pollination treatment for each of the seven possible days). The resulting hard kernels could be distinguished from the shriveled sweet kernels. The time of pollination had a strong effect on kernel set. The highest percentage of daily kernel set was observed on the first day of silking (Day 1). It accounted for 31 (2007) and 42% (2008) of the total kernels per ear. The distribution of these kernels followed a bell-shaped curve with a peak at around the position of the tenth kernel from the bottom of the ear. On the following days, kernel set followed a double bell-shaped curve with the peak shifting to the tip of the ear followed by a steady decrease. The minor peak, at the bottom of the ears, almost disappeared by Day 4 of silking. More than 90% of the final number of kernels was set within five (2007) or three (2008) days. The visual marker system successfully traced the dynamics of silk emergence and its impact on kernel set as well as its dependence on environmental conditions during flowering.
Published in: Crop science
Volume: 50
Issue: 6
Pages: 2499 - 2505
ISSN: 0011-183X
Publication date / Date received: 2010-01-01
Publication status: Madison, WI
Publication status: Published
Subjects: Landwirtschaft allgemein|Agriculture, General
Language: English
Review status: Peer reviewed
DBID source: FORM-1291803228, WOS-000284134000032
DOI: 10.2135/cropsci2010.04.0196
Nebis system number: 000036710
, Rast, Helen, Liedgens, Markus, Sangakkara, U.R., Stamp, Peter, 2010 >>
Author(s): Rast, Helen, Liedgens, Markus, Sangakkara, U.R., Stamp, Peter
Title: Early Growth of Crotalaria (Crotalaria juncea), Tithonia (Tithonia diversifolia), and Maize (Zea mays) as Affected by Soil Fertility and Phosphorus Fertilizer under Pot and Field Conditions
Abstract: Green manures are important in tropical cropping systems and are planted in degraded soils, thus affecting early growth. Pot and field experiments evaluated the impact of soil fertility on early growth of two important tropical green manures (Crotalaria juncea and Tithonia diversifolia) when compared to that of maize (Zea mays) with high and low levels of phosphorus fertilizer. Growth of tithonia was not affected by soil fertility level irrespective of phosphorus fertilizer, indicating its suitability for degraded soils. Crotalaria was affected by soil fertility (root growth was stimulated by phosphorus), indicating its potential for soils with some degree of fertility. Maize was significantly affected by soil fertility and phosphorus fertilizers, indicating the requirement of fertile soils for the successful development of a good root and shoot system. The importance of field studies in the tropics is also presented as the diverse field conditions reduces significant effects found in pot studies.
Published in: Communications in soil science and plant analysis
Volume: 41
Issue: 14
Pages: 1655 - 1664
ISSN: 0010-3624, 1532-2416
Publication date / Date received: 2010-01-01
Publication status: Philadelphia, PA
Publication status: Published
Subjects: Early growth, green manure crops, maize, phosphorus fertilizer, soil fertility
Language: English
Review status: Peer reviewed
Keyword: Early growth, green manure crops, maize, phosphorus fertilizer, soil fertility
DBID source: FORM-1291813970
DOI: 10.1080/00103624.2010.488710
Nebis system number: 000036687
, Noulas, Christos, Liedgens, Markus, Stamp, Peter, Alexiou, Ioannis, Herrera, Juan M., 2010 >>
Author(s): Noulas, Christos, Liedgens, Markus, Stamp, Peter, Alexiou, Ioannis, Herrera, Juan M.
Title: Subsoil Root Growth of Field Grown Spring Wheat Genotypes (Triticum Aestivum L.) Differing in Nitrogen Use Efficiency Parameters
Abstract: In a two-year (1999-2000) field experiment four Swiss spring wheat (Triticum aestivum L.) genotypes (cvs. 'Albis', 'Toronit' and 'Pizol' and an experimental line 'L94491') were compared for genotypic differences in the root parameters that determine uptake potential and nitrogen use efficiency (NUE):root surface area (RSA) and its components, root length density (RLD) and the diameter of the roots. The genotypes were grown under no (N0) and under ample fertilizer nitrogen (N) [ammonium nitrate (NH4NO3); N1; 250 kg N ha-1] supply. Root samples were taken from all the genotypes at anthesis from the subsoil (30-60 cm). Genotypic effects on RLD and RSA were evident only in 2000 and large amounts of N fertilizer usually diminished root growth. Adequate soil moisture in 1999 may have favored the establishment of the root system of all the genotypes before anthesis. Parameters of NUE for each genotype were also determined at anthesis and at physiological maturity. 'Albis' the least efficient cv. in recovering fertilizer N (ranged from 36.5 to 61.1%) with the lowest N uptake efficiency (0.47 to 0.79 kg kg-1) had the lowest RLD and RSA in both seasons. Among genotypes 'Toronit', a high-yielding cv., efficient in recovering fertilizer N, exhibited the higher NUE (22.4 to 29.3 kg kg-1) and tended to have the highest values of RLD and RSA. Nitrogen fertilization also led to an increase in the proportion of roots with diameters less than 300 m and decreased the proportion of roots with diameters of 300 to 700 m. These trends were more pronounced for cv. 'Pizol' in 1999 and for cv. 'Toronit' in 1999 and 2000. By anthesis in a humid temperate climate, there are no marked differences in the subsoil root growth of the examined genotypes. Some peculiarities on the root growth characteristics of the cultivars 'Albis' and 'Toronit' may partially explain their different NUE performance.
Published in: Journal of plant nutrition
Volume: 33
Issue: 13
Pages: 1887 - 1903
ISSN: 0190-4167, 1532-4087
Publication date / Date received: 2010-01-01
Publication status: London, UK
Publication status: Published
Subjects: Biologie allgemein|Biology, General, Wheat, Root length density, Root surface area, Root diameter classes, Nitrogen use efficiency parameters
Language: English
Review status: Peer reviewed
Keyword: Wheat, Root length density, Root surface area, Root diameter classes, Nitrogen use efficiency parameters
DBID source: WOS-000281903100001
DOI: 10.1080/01904167.2010.512049
Nebis system number: 000006331
, Munsch, Magali A., Stamp, Peter, Christov, Nikolai K., Foueillassar, Xavier M., Huesken, Alexandra, Camp, Karl-Heinz, Weider, Christophe, 2010 >>
Author(s): Munsch, Magali A., Stamp, Peter, Christov, Nikolai K., Foueillassar, Xavier M., Huesken, Alexandra, Camp, Karl-Heinz, Weider, Christophe
Title: Grain Yield Increase and Pollen Containment by Plus-Hybrids Could Improve Acceptance of Transgenic Maize
Abstract: Maize (Zea mays L.) Plus-Hybrids are a blend of cytoplasmic male-sterile (CMS) hybrids and unrelated male-fertile hybrids ensuring pollination of the whole stand. Combining potential benefits of male sterility (CMS effect) and allo-pollination (xenia effect), they often outperform the corresponding male-fertile sib-pollinated hybrids in terms of yield. The combining abilities of five CMS hybrids and eight pollinators were investigated in a factorial split-plot design in 12 environments in four countries and two years. The plant material from different breeders represented the three types of male-sterile cytoplasm. Plus-Hybrids increased grain yield, on average, by 10% or more and by up to 20% in specific environments. Three highly responsive CMS hybrids and four generally good pollinators were identified. The Plus-Hybrid effect affected both yield components, CMS leading mainly to a higher number of kernels (KN) and the xenia effect mainly to an increase in the thousand kernel weight (TKW). Despite some differences in the response of the three types of CMS, the effect of the cytoplasm was not significant. While the CMS effect depended strongly on environment, the xenia was consistent in all environments but its extent varied. As well as increasing yield, we can expect that Plus-Hybrids can make a large contribution to the coexistence of transgenic and conventional maize by biocontainment, that is eliminating or reducing the release of transgenic pollen in Bacillus thuringiensis (Bt) maize or herbicide-tolerant (HT) maize.
Published in: Crop science
Volume: 50
Issue: 3
Pages: 909 - 919
ISSN: 0011-183X
Publication date / Date received: 2010-01-01
Publication status: Madison, WI
Publication status: Published
Language: English
Review status: Peer reviewed
DBID source: WOS-000276961900019
DOI: 10.2135/cropsci2009.03.0117
Nebis system number: 000036710
, Hund, Andreas, 2010 >>
Author(s): Hund, Andreas
Title: Genetic variation in root architecture of maize and its response to abiotic stresses
Publication date / Date received: 2010-01-01
Publication status: Zürich
Publication status: Published
Language: English
Review status: Peer reviewed
DBID source: FORM-1294243734
, Herrera, Juan M., Feil, Boy, Stamp, Peter, Liedgens, Markus, 2010 >>
Author(s): Herrera, Juan M., Feil, Boy, Stamp, Peter, Liedgens, Markus
Title: Root Growth and Nitrate-Nitrogen Leaching of Catch Crops following Spring Wheat
Abstract: Growing nitrogen (N) catch crops can reduce NO3-N leaching after cultivating cereals The objective of this study was to relate NO3-N leaching to variation in the uptake of N and the size and distribution of the root systems of different catch crops species. In a 3-yr lysimeter experiment, phacelia (Phacelia tanacetifolia Benth), sunflower (Helianthus annuns L), and a Brassica species (yellow mustard [Brassica alba L] or a hybrid of turnip rape [B rape L spp. oleifera (DC) Metzg] and Chinese cabbage [B rape L ssp chinensis (L) Hanelt]) were grown after the harvest of spring wheat under two levels of N supply. Bare soil lysimeters served as the control. Water percolation from the lysimeters and the NO3- concentration in the leachate were measured weekly from the sowing until the presumed frost-kill of the catch crops Minirhizotrons were used to assess the spatial and temporal patterns of root growth from 0 10 to 1 00 m The catch crop species differed in their shoot biomass, N uptake. total NO3-N leaching, and root growth The results suggested that diet e was no strict relationship between the total NO3-N leaching of each catch crop species and the N uptake or parameters that indicate static characteristics of the root system In contrast. the ranking of each catch crop species by parameters that indicate early root growth was inversely related to the ranking of each catch crop species in NO3-N leaching The rapid establishment of the root system is essential for a catch crop following spring wheat to reduce the amount of NO3-N leaching after the harvest of spring wheat.
Published in: Journal of environmental quality
Volume: 39
Issue: 3
Pages: 845 - 854
ISSN: 0047-2425, 1537-2537
Publication date / Date received: 2010-01-01
Publication status: Madison, WI
Publication status: Published
Language: English
Review status: Peer reviewed
DBID source: WOS-000277129100009
DOI: 10.2134/jeq2009.0306
Nebis system number: 000013890
, Faget, Marc, Liedgens, Markus, Stamp, Peter, Fluetsch, Patrick, Herrera, Juan Manuel, 2010 >>
Author(s): Faget, Marc, Liedgens, Markus, Stamp, Peter, Fluetsch, Patrick, Herrera, Juan Manuel
Title: A minirhizotron imaging system to identify roots expressing the green fluorescent protein
Abstract: The limited flexibility available in the configuration of commercial minirhizotron imaging systems makes it difficult to adapt these systems to new applications. It is also too expensive to introduce modifications, which are often very temporary to these systems at the end of the development process. In order to identify the roots of a single species in mixed plant stands, we developed a new minirhizotron imaging system that makes it possible to observe roots expressing green fluorescent protein (GFP). This system is based on affordable and easily obtainable components such as webcams. Here, we report a protocol to identify suitable webcams for constructing a minirhizotron imaging system and demonstrate the application of this protocol to build a minirhizotron imaging system that can identify the roots of a transformed maize plant expressing GFP.
Published in: Computers and electronics in agriculture
Volume: 74
Issue: 1
Pages: 163 - 167
ISSN: 0168-1699
Publication date / Date received: 2010-01-01
Publication status: Amsterdam
Publication status: Published
Subjects: Roots, Minirhizotron, Webcam, Imaging, Green fluorescent protein
Language: English
Review status: Peer reviewed
Keyword: Roots, Minirhizotron, Webcam, Imaging, Green fluorescent protein
DBID source: WOS-000283271800017
DOI: 10.1016/j.compag.2010.06.010
Nebis system number: 000031772
, Eschholz, T. W., Stamp, P., Peter, R., Leipner, J., Hund, A., 2010 >>
Author(s): Eschholz, T. W., Stamp, P., Peter, R., Leipner, J., Hund, A.
Title: Genetic structure and history of Swiss maize (Zea mays L. ssp mays) landraces
Abstract: Between 1930 and 2003 with emphasis on the 1940s maize landraces (Zea mays L. ssp. mays) from all over Switzerland were collected for maintenance and further use in a new Swiss breeding program. The genetic relationship and diversity among these accessions stored in the Swiss gene bank is largely unknown. Our hypothesis was that due to the unique geographic, climatic, and cultural diversity in Switzerland a diverse population of maize landraces had developed over the past three centuries. The aims were to characterize the genetic diversity of the Swiss landraces and their genetic relationship with accessions from neighbouring regions as well as reviewing their history, collection, and maintenance. The characterization and grouping was based on analyses with ten microsatellite markers. Geographic, cultural, and climatic conditions explained a division in two distinct groups of accessions. One group consisted of landraces collected in the southern parts of Switzerland. This group was related to the Italian Orange Flints. The other group contained accessions from northern Switzerland which were related to Northern European Flints in particular German Flints. Historic evidence was found for a frequent exchange of landraces within the country resulting in a lack of region-specific or landrace-specific genetic groups. The relatively large separation between the accessions, indicated by high F (ST) (0.42), might be explained partly by a bottleneck during the collection and maintenance phase as well as by geographical and cultural separation of north and south of the country. Due to the high genetic diversity, the accessions here are a potential resource for broadening the European flint pool.
Published in: Genetic resources and crop evolution
Volume: 57
Issue: 1
Pages: 71 - 84
ISSN: 0925-9864, 1573-5109
Publication date / Date received: 2010-01-01
Publication status: Berlin
Publication status: Published
Subjects: Corn/maize, Flint, Germplasm collection, History, Landrace, Open pollinated variety, Rheintaler, Zea mays
Language: English
Review status: Peer reviewed
Keyword: Corn/maize, Flint, Germplasm collection, History, Landrace, Open pollinated variety, Rheintaler, Zea mays
DBID source: WOS-000273809800007
DOI: 10.1007/s10722-009-9452-0
Nebis system number: 000695663
, Vogler, André, Eisenbeiss, Henri, Aulinger-Leipner, Ingrid, Stamp, Peter, 2009 >>
Author(s): Vogler, André, Eisenbeiss, Henri, Aulinger-Leipner, Ingrid, Stamp, Peter
Title: Impact of topography on cross-pollination in maize (Zea mays L.)
Abstract: Understanding cross-pollination is important to achieve the coexistence of genetically modified (GM) and conventional maize (Zea mays L.); it is still not known whether topography favors or hinders cross-pollination. In 2005 and 2006, the effect of gradients of 3.4–6.8° on cross-pollination was investigated in the canton of Zurich, Switzerland. Cross-pollination was revealed by the presence of yellow-grains on a white-grain hybrid at distances up to 17.5 m from the yellow-grain pollen donor hybrid. The measurements of the inclination of the slope were based on aerial images data taken by an unmanned GPS/INS (Global Positioning System/Inertial Navigation System)-based and stabilized model helicopter, which delivered precise altitude-based data for sampling points at tassel height. The rate of cross-pollination increased significantly with decreasing altitude of the receptor field (r = 0.36–0.64). However, the effect seems to be weaker than that of other factors like wind direction and velocity.
Published in: European journal of agronomy
Volume: 31
Issue: 2
Pages: 99 - 102
ISSN: 1161-0301
Publication date / Date received: 2009-01-01
Publication status: Amsterdam
Publication status: Published
Subjects: Landwirtschaft allgemein|Agriculture, General, Cross-pollination, Maize, Inclination, Topography, Coexistence, GIS, Unmanned aerial vehicle, Photogrammetry
Language: English
Review status: Peer reviewed
Keyword: Cross-pollination, Maize, Inclination, Topography, Coexistence, GIS, Unmanned aerial vehicle, Photogrammetry
DBID source: PP-51343, PP-53762
DOI: 10.1016/j.eja.2009.04.003
Nebis system number: 000650747
, Trachsel, Samuel, Messmer, Rainer, Stamp, Peter, Hund, Andreas, 2009 >>
Author(s): Trachsel, Samuel, Messmer, Rainer, Stamp, Peter, Hund, Andreas
Title: Mapping of QTLs for lateral and axile root growth of tropical maize
Abstract: Maize genotypes may adapt to dry environments by avoiding desiccation by means of a deeper root system or by maintaining growth and water extraction at low water potentials. The aim of this study was to determine the quantitative genetic control of root growth and root morphology in a population of 236 recombinant inbred lines (RILs) from the cross between CML444 (high-yielding) × SC-Malawi (low-yielding), which segregates for the response to drought stress at flowering. The RILs and the parental lines were grown on blotting paper in growth pouches until the two-leaf stage under non-stressed conditions; the parents were additionally exposed to desiccation stress induced by polyethylene glycol with a molecular weight of 8000 Dalton (PEG-8000). The lengths of axile and lateral roots were measured non-destructively at 2, 5, 7 and 9 days after germination, by scanning with an A4 scanner followed by digital image analysis. CML444 had a lower rate constant of lateral root elongation (kLat) than SC-Malawi, but the two genotypes did not differ in their response to desiccation. QTLs affecting root vigor, as depicted by increments in kLat, the elongation rate of axile roots (ERAx) and the number of axile roots (NoAx) were identified in bins 2.04 and 2.05. QTLs for NoAx and ERAx collocated with QTLs for yield parameters in bins 1.03–1.04 and 7.03–04. The correspondence of QTLs for axile root traits in bins 1.02–1.03 and 1.08 and QTLs for lateral roots traits in bins 2.04–2.07 in several mapping populations suggests the presence of genes controlling root growth in a wide range of genetic backgrounds.
Published in: Theoretical and applied genetics
Volume: 119
Issue: 8
Pages: 1413 - 1424
ISSN: 0040-5752, 1432-2242
Publication date / Date received: 2009-01-01
Publication status: Berlin
Publication status: Published
Language: English
Review status: Peer reviewed
DBID source: PP-53760, WOS-000271504700006
DOI: 10.1007/s00122-009-1144-9
Nebis system number: 000985869
, Roux, Michel, 2009 >>
Author(s): Roux, Michel
Title: Peter Stamp
Subtitle: Wir setzen alles daran, das gentische Potential der grossen Kulturpflanzen voll auszuschöpfen
Abstract: Seit 21 Jahren forscht und lehrt Peter Stamp als Professor für Agronomie und Pflanzenzüchtung an der ETH Zürich. Im Januar 2011 wird er emeritiert. Er sieht die Schweiz als Vorbild für einen produktiven und nachhaltigen Pflanzenbau. Peter Stamp fait de la recherche et de 'enseignement depuis 21 ans en tant que professeur d'agronomie et de sélection végétale � l'EPF Zurich. En janvier 2011 il prendra sa retraite. Deux de ses souhaits pour le futur: La recherche végétale doit tout mettre en oeuvre afin de tirer le maximum du potentiel génétique des principales plantes cultivées. Faute de quoi, il ne sera pas possible d'atteindre l'objectif fixé actuellement que est de doubler la production végétale d'ici 2050. Pour ce faire, les plantes devront cependant être mieux adaptées qu'aujourd'hui aux systèmes agro-écologiques et aux types de climat correspondants. Ceci est une lourde tâche. Deuxième souhait: L'EPF Zurich forme d'excellents spécialistes en production végétale, avec une renommée internationale. Cependant, ils ne sont pas assez nombreux. Il en faudra nettement plus.
Published in: Journal : Ingenieure ETH Agrar, Lebensmittel, Umwelt
Issue: 43/44
Pages: 4 - 6
Publication date / Date received: 2009-01-01
Publication status: Zollikofen
Publication status: Published
Language: German
Review status: Internally reviewed
DBID source: PP-54571, PP-56597
Nebis system number: 002044612
, Leipner, Jörg, 2009 >>
Author(s): Leipner, Jörg
Title: Chilling stress in maize
Subtitle: From physiology to genetics and molecular mechanisms
Publication date / Date received: 2009-01-01
Publication status: Zurich
Publication status: Published
Subjects: Acker- und Futterbau (inkl. Kultur- und Nutzpflanzen) | Crop and Fodder Farming (incl. Cultivated and Crop Plants), Botanik |Botany
Language: English
Review status: Peer reviewed
DBID source: FORM-1294243858
DOI: 10.3929/ethz-a-005794605
, Hund, Andreas, Ruta, Nathinee, Liedgens, Markus, 2009 >>
Author(s): Hund, Andreas, Ruta, Nathinee, Liedgens, Markus
Title: Rooting depth and water use efficiency of tropical maize inbred lines, differing in drought tolerance
Abstract: Deep rooting has been identified as strategy for desiccation avoidance in natural vegetation as well as in crops like rice and sorghum. The objectives of this study were to determine root morphology and water uptake of four inbred lines of tropical maize (Zea mays L.) differing in their adaptation to drought. The specific questions were i) if drought tolerance was related to the vertical distribution of the roots, ii) whether root distribution was adaptive or constitutive, and iii) whether it affected water extraction, water status, and water use efficiency (WUE) of the plant. In the main experiment, seedlings were grown to the V5 stage in growth columns (0.80 m high) under well-watered (WW) and water-stressed (WS) conditions. The depth above which 95 % of all roots were located (D95) was used to estimate rooting depth. It was generally greater for CML444 and Ac7729/TZSRW (P2) compared to SC-Malawi and Ac7643 (P1). The latter had more lateral roots, mainly in the upper part of the soil column. The increase in D95 was accompanied by increases in transpiration, shoot dry weight, stomatal conductance and relative water content without adverse effects on the WUE. Differences in the morphology were confirmed in the V8 stage in large boxes: CML444 with thicker (0.14 mm) and longer (0.32 m) crown roots compared to SC-Malawi. Deep rooting, drought sensitive P2 showed markedly reduced WUE, likely due to an inefficient photosynthesis. The data suggest that a combination of high WUE and sufficient water acquisition by a deep root system can increase drought tolerance.
Published in: Plant and soil
Volume: 318
Issue: 1-2
Pages: 311 - 325
ISSN: 0032-079X, 1573-5036
Publication date / Date received: 2009-01-01
Publication status: Berlin
Publication status: Published
Subjects: Drought avoidance, Root length density, Root morphology, Stomatal conductance, Water use efficiency, Zea mays L
Language: English
Review status: Peer reviewed
Keyword: Drought avoidance, Root length density, Root morphology, Stomatal conductance, Water use efficiency, Zea mays L
DBID source: PP-53735
DOI: 10.1007/s11104-008-9843-6
Nebis system number: 000052447
, Faget, Marc, Herrera, Juan M., Stamp, Peter, Aulinger-Leipner, Ingrid, Frossard, Emmanuel, Liedgens, Markus, 2009 >>
Author(s): Faget, Marc, Herrera, Juan M., Stamp, Peter, Aulinger-Leipner, Ingrid, Frossard, Emmanuel, Liedgens, Markus
Title: The use of green fluorescent protein as a tool to identify roots in mixed plant stands
Abstract: Roots take up most of the resources required by a plant, but a lack of efficient research tools hinders our understanding of the function and relevance of the root system. This is especially evident when the research focus is not on a single plant, but on multiple plants that share the same soil resources. None of the available methods allow for simple, inexpensive, non-destructive, and objective assignment of observed roots in a mixture of plants to a target plant. Here, we demonstrate that transgenic plants expressing the green fluorescent protein (GFP), combined with the well established minirhizotron technique, is a route to overcoming this limitation. We planted transgenic maize (Zea mays L.) in combination with either its corresponding wild type, Italian ryegrass (Lolium multiflorum Lam.), or soybean (Glycine max (L.) Merr.). Identification of fluorescent roots allows the relative distribution of roots of each plant type and their interaction and interference with each other to be observed. The selected plants are suitable for model experiments to unravel fundamental belowground ecological processes. Because genetic transformation of plants is an established technique that can be applied to a large set of plant species, this method will be of interest to a broad range of research areas.
Published in: Functional plant biology
Volume: 36
Issue: 10-11
Pages: 930 - 937
ISSN: 1445-4408
Publication date / Date received: 2009-01-01
Publication status: Collingwood
Publication status: Published
Subjects: imaging system, minirhizotron, root research methodology, root interactions
Event name: 1st International Plant Phenomics Symposium (IPPS 2009)
Event date: April 21-24, 2009
Place: Canberra, Australia
Language: English
Review status: Peer reviewed
Keyword: imaging system, minirhizotron, root research methodology, root interactions
DBID source: PP-51215, PP-53731, WOS-000271464600011
DOI: 10.1071/FP09125
Nebis system number: 004240289
, Waldispühl, S., Stamp, P., Streit, B., 2008 >>
Author(s): Waldispühl, S., Stamp, P., Streit, B.
Title: Effect of tillage systems and herbicides on the control of Yellow Nutsedge (Cyperus esculentus L.) in maize
Published in: Journal of plant diseases and protection
Issue: Sp. Iss. 21
Pages: 509 - 514
ISSN: 1861-3829, 0340-8159, 1861-3837
Publication date / Date received: 2008-01-01
Publication status: Stuttgart
Publication status: Published
Event name: 24th German Conference on Weed Biology and Weed Control
Event date: March 4-6, 2008
Place: Stuttgart-Hohenheim, Germany
Language: English
Review status: Peer reviewed
DBID source: PP-42061, WOS-000255966400088
Nebis system number: 000039466
, Sangakkara, U. R., Stamp, Peter, 2008 >>
Author(s): Sangakkara, U. R., Stamp, Peter
Title: Impact of improved fallow periods on soil properties and productivity of maize (Zea mays L.) in major and minor seasons of Asian humid tropics
Abstract: Improved fallows are considered an easy, low cost and suitable method of increasing the productivity and sustainability of smallholder tropical rainfed cropping systems, although most farmers allow weeds to grow when the environmental conditions are not conductive for crop production. Field studies were carried out over the minor and major seasons, to evaluate the impact of a preceding improved fallow using Crotalaria or Tithonia , two popular tropical green manures, on selected soil properties, and on the growth and yield of maize. Improved fallows enhanced chemical soil properties significantly and the impact was most prominent at the onset of the minor maize season. Thus, the growth and yield of maize was also increased to a greater extent in this season, when yields are generally lower due to the suboptimal climatic conditions of lower rainfall and higher temperatures. However, fallows in the minor season also improved soil characteristics and maize yields in the major season, the most significant impact being increased seed yields and harvest indices. Although farmers may not grow fallow crops in major seasons, the potential of these green manure fallows in increasing maize yields in minor seasons and possible strategies to include the fallows in the cropping sequences of tropical rainfed upland cropping systems are discussed on the basis of this field study.
Published in: Acta Agronomica Hungarica
Volume: 56
Issue: 3
Pages: 303 - 312
ISSN: 0001-513X, 0238-0161
Publication date / Date received: 2008-01-01
Publication status: Budapest
Publication status: Published
Subjects: improved fallows, soil improvement, maize yields, humid tropics
Language: English
Review status: Peer reviewed
Keyword: improved fallows, soil improvement, maize yields, humid tropics
DBID source: PP-42058
DOI: 10.1556/AAgr.56.2008.3.6
Nebis system number: 000041500
, Sangakkara, U. R., Nissanka, S. P., Stamp, P., 2008 >>
Author(s): Sangakkara, U. R., Nissanka, S. P., Stamp, P.
Title: Effects of organic matter and time of incorporation on root development of tropical maize seedlings
Abstract: Smallholders in the tropics add different organic materials to their crops at different times, based on the availability of materials and labour. However, the time of application could have an effect on the establishment and early growth of crops, especially their root systems, which has not yet been clearly identified. This paper presents the results of a study conducted under greenhouse conditions using soils from a field treated with three organic materials at 4 or 2 weeks before or at the planting of maize seeds, corresponding to the times that tropical smallholders apply these materials. The organic materials used were leaves of Gliricidia sepium and Tithonia diversifolia or rice straw, incorporated at a rate equivalent to 6 Mt ha −1 . A control treatment where no organic matter was added was used for comparison. The impact of the treatments on soil properties at the planting of maize seed and detailed root analysis based on root lengths were carried out until the last growth stage (V4). The addition of organic matter improved the soil characteristics, and the impact of adding Gliricidia leaves was most pronounced when incorporated 2 weeks before planting. The benefits of leaves of Tithonia or rice straw on soil quality parameters were clearly evident when added 4 weeks before planting. Organic matter enhanced the root number, root length, root growth rate and branching indices. All the organic materials suppressed the growth of maize roots when applied at planting, suggesting the existence of allelopathic effects, which could result in poor growth. The most benefits in terms of root growth were observed with Tithonia.
Published in: Acta Agronomica Hungarica
Volume: 56
Issue: 2
Pages: 169 - 178
ISSN: 0238-0161, 1588-2527
Publication date / Date received: 2008-01-01
Publication status: Budapest
Publication status: Published
Subjects: maize, organic matter, time of application, root growth
Language: English
Review status: Peer reviewed
Keyword: maize, organic matter, time of application, root growth
DBID source: PP-42059
DOI: 10.1556/AAgr.56.2008.2.6
, Sangakkara, Ravi, Attanayake, K. B., Stamp, Peter, 2008 >>
Author(s): Sangakkara, Ravi, Attanayake, K. B., Stamp, Peter
Title: Impact of locally derived organic materials and method of addition on maize yields and nitrogen use efficiencies in major and minor seasons of tropical South Asia
Abstract: Maize is the most important highland cereal grown in the tropics, generally cultivated under rainfed smallholder conditions in Asia. Field experiments were carried out in Sri Lanka with the objective of determining the impact of three types of organic matter applied as mulch or incorporated on the yields and nitrogen uptake by maize cultivated under rainfed conditions in the South Asian major and minor seasons. The organic matter used was leaves of Gliricidia sepium, Tithonia diversifolia, or rice straw, with the full compliment of recommended mineral fertilizers. Organic matter, especially the two green manures, enhanced yields and nitrogen (N) uptake of maize, and the impact was more prominent in the minor dry season where the yields were lower. Incorporation of organic matter had a greater positive impact in the dry season in terms of N utilization efficiency and seed yields. The beneficial impact of organic matter with low carbon (C):N ratios in enhancing N nutrition and seed yields of rainfed maize in major and more importantly in the minor seasons is presented.
Published in: Communications in Soil Science and Plant Analysis
Volume: 39
Issue: 17/18
Pages: 2584 - 2596
ISSN: 0010-3624, 1532-2416
Publication date / Date received: 2008-01-01
Publication status: Philadelphia, PA
Publication status: Published
Subjects: Maize, nitrogen use efficiency, organic matter, seed yields, tropical seasons
Language: English
Review status: Peer reviewed
Keyword: Maize, nitrogen use efficiency, organic matter, seed yields, tropical seasons
DBID source: PP-42060
DOI: 10.1080/00103620802358623
Nebis system number: 000036687
, Rieger, S., Richner, W., Streit, B., Frossard, E., Liedgens, M., 2008 >>
Author(s): Rieger, S., Richner, W., Streit, B., Frossard, E., Liedgens, M.
Title: Growth, yield, and yield components of winter wheat and the effects of tillage intensity, preceding crops, and N fertilisation
Abstract: Conservation tillage is widely practiced in semi-arid climates, mostly in small grain crop rotations. It is implemented to a much lesser extent in cool and humid climates of Europe, mainly due to a lack of knowledge about agronomic and ecological impacts. This study was conducted in light- to medium-textured soils in the Swiss midlands from 1995 to 2000. The aim was to determine whether tillage intensity impacted wheat yield and measure the effects of the preceding crop and the level of N fertilisation. Conventional tillage (CT) with ploughing, minimum tillage (MT) with a chisel, and no-tillage (NT) were studied in the following crop rotation: winter wheat (Triticum aestivum L.)–oilseed rape (Brassica napus L.)–winter wheat–maize (Zea mays L.). Winter wheat was grown at either 0 kg N ha−1 (N0) or at the recommended N supply (N1). Harvest residues of all the crops were left on the field. In the early stages wheat development under NT was slightly slower than under CT and MT, but at maturity the shoot biomass was 2% higher under NT than under the other tillages. The grain yield decreased by 3% under NT compared to CT and MT, mainly due to fewer ears per area and a significantly lower thousand-kernel weight. Wheat planted after oilseed rape had significantly higher shoot biomass and grain yield than wheat planted after maize. At the beginning of the vegetation season there were small but significant differences in the soil mineral N content among the tillage treatments. Accordingly, the level of N fertiliser applied was adjusted to ensure similar N availability in all tillage systems. The relative reduction in grain yield under NT compared to CT and MT was similar with and without N fertilisation. Thus, N availability was not a limiting factor for the yield of NT wheat in this study.
Published in: European journal of agronomy
Volume: 28
Issue: 3
Pages: 405 - 411
ISSN: 1161-0301
Publication date / Date received: 2008-01-01
Publication status: Amsterdam
Publication status: Published
Subjects: Winter wheat, Tillage intensity, Yield, Crop rotation
Language: English
Review status: Peer reviewed
Keyword: Winter wheat, Tillage intensity, Yield, Crop rotation
DBID source: PP-42057
DOI: 10.1016/j.eja.2007.11.006
Nebis system number: 000650747
, Massacci, A., Nabiev, S.M., Pietrosanti, L., Nematov, S.K., Chernikova, T.N., Thor, K., Leipner, J., 2008 >>
Author(s): Massacci, A., Nabiev, S.M., Pietrosanti, L., Nematov, S.K., Chernikova, T.N., Thor, K., Leipner, J.
Title: Response of the photosynthetic apparatus of cotton (Gossypium hirsutum) to the onset of drought stress under field conditions studied by gas-exchange analysis and chlorophyll fluorescence imaging
Abstract: The functioning of the photosynthetic apparatus of cotton (Gossypium hirsutum) grown during the onset of water limitation was studied by gas-exchange and chlorophyll fluorescence to better understand the adaptation mechanisms of the photosynthetic apparatus to drought conditions. For this, cotton was grown in the field in Central Asia under well-irrigated and moderately drought-stressed conditions. The light and CO2 responses of photosynthesis (AG), stomatal conductance (gs) and various chlorophyll fluorescence parameters were determined simultaneously. Furthermore, chlorophyll fluorescence images were taken from leaves to study the spatial pattern of photosystem II (PSII) efficiency and non-photochemical quenching parameters. Under low and moderate light intensity, the onset of drought stress caused an increase in the operating quantum efficiency of PSII photochemistry (PSII) which indicated increased photorespiration since photosynthesis was hardly affected by water limitation. The increase in PSII was caused by an increase of the efficiency of open PSII reaction centers (Fv′/Fm′) and by a decrease of the basal non-photochemical quenching (NO). Using a chlorophyll fluorescence imaging system a low spatial heterogeneity of PSII was revealed under both irrigation treatments. The increased rate of photorespiration in plants during the onset of drought stress can be seen as an acclimation process to avoid an over-excitation of PSII under more severe drought conditions.
Published in: Plant physiology and biochemistry
Volume: 46
Issue: 2
Pages: 189 - 195
ISSN: 0981-9428
Publication date / Date received: 2008-01-01
Publication status: Paris
Publication status: Published
Subjects: Chlorophyll fluorescence imaging, Drought acclimation, Gossypium hirsutum, Photorespiration, Photosynthesis, Stomatal conductance
Language: English
Review status: Peer reviewed
Keyword: Chlorophyll fluorescence imaging, Drought acclimation, Gossypium hirsutum, Photorespiration, Photosynthesis, Stomatal conductance
DBID source: PP-37006
DOI: 10.1016/j.plaphy.2007.10.006
Nebis system number: 000037518
, Leipner, Jörg, Jompuk, Choosak, Camp, Karl-Heinz, Stamp, Peter, Fracheboud, Yvan, 2008 >>
Author(s): Leipner, Jörg, Jompuk, Choosak, Camp, Karl-Heinz, Stamp, Peter, Fracheboud, Yvan
Title: QTL studies reveal little relevance of chilling-related seedling traits for yield in maize
Abstract: Prolonged low temperature phases and short-term cold spells often occur in spring during the crucial stages of early maize (Zea mays L.) development. The effect of low temperature-induced growth retardation at the seedling stage on final yield is poorly studied. Therefore, the aim was to identify genomic regions associated with morpho-physiological traits at flowering and harvest stage and their relationship to previously identified quantitative trait loci (QTLs) for photosynthesis and morpho-physiological traits from the same plants at seedling stage. Flowering time, plant height and shoot biomass components at harvest were measured in a dent mapping population for cold tolerance studies, which was sown in the Swiss Midlands in early and late spring in two consecutive years. Early-sown plants exhibited chilling stress during seedling stage, whereas late-sown plants grew under favorable conditions. Significant QTLs, which were stable across environments, were found for plant height and for the time of flowering. The QTLs for flowering were frequently co-localized with QTLs for plant height or ear dry weight. The comparison with QTLs detected at seedling stage revealed only few common QTLs. A pleiotropic effect was found on chromosome 3 which revealed that a good photosynthetic performance of the seedling under warm conditions had a beneficial effect on plant height and partially on biomass at harvest. However, a high chilling tolerance of the seedling seemingly had an insignificant or small negative effect on the yield.
Published in: Theoretical and Applied Genetics
Volume: 116
Issue: 4
Pages: 555 - 562
ISSN: 0040-5752, 1432-2242
Publication date / Date received: 2008-01-01
Publication status: Berlin
Publication status: Published
Language: English
Review status: Peer reviewed
DBID source: PP-42056
DOI: 10.1007/s00122-007-0690-2
Nebis system number: 000985869
, Kölliker, Roland, Gaume, Alain, Hund, Andreas, Winzeler, Michael, Einsele, Arthur, 2008 >>
Author(s): Kölliker, Roland, Gaume, Alain, Hund, Andreas, Winzeler, Michael, Einsele, Arthur
Title: Eine Vision für den Schweizer Pflanzenbau im Jahr 2050
Abstract: 2050 werden die Rahmenbedingungen für den Pflanzenbau in der Schweiz nicht wieder zu erkennen sein. Hauptursachen dafür sind globale und freie Märkte mit stärkerem Wettbewerbsdruck, der Klimawandel mit häufigeren Extremereignissen sowie die knapper werdenden Ressourcen: Die Bodenqualität verschlechtert sich, das ackerfähige Land schwindet und Wasser wird nicht mehr jeder Zeit frei verfügbar sein. Ist unter diesen Umständen ein produktiver Pflanzenbau in der Schweiz überhaupt noch möglich und sinnvoll? Was braucht es um einen zukunftsfähigen Pflanzenbau zu ermöglichen? Diese Fragen stellten sich Expertinnen und Experten unter der Leitung der Schweizerischen Gesellschaft für Pflanzenbauwissenschaften (SGPW) im Projekt Vision Pflanzenbau 2050. Die Studie kommt zum Schluss, dass nur auf der Basis von wissenschaftlichen und technologischen Neuerungen im Pflanzenbau die Landwirtschaft auch im Jahr 2050 noch genügend qualitativ hochwertige Nahrungsmittel produzieren kann. Eng damit gekoppelt sind die Erhaltung der Produktionsflächen sowie der notwendigen gesellschaftlichen Güter wie Landschaft zur Erholung, gesicherte Trinkwasserversorgung oder der Erhalt der Biodiversität. Die SGPW zeigt den aktuellen Forschungs- und Entwicklungsbedarf auf, um einen qualitativ und quantitativ hochstehenden Pflanzenbau für die Zukunft zu ermöglichen. En 2050, les conditions cadre pour la production végétale ne seront plus reconnaissables. Les raisons principales en sont les marchés globalisés et libéralisés avec une pression concurrentielle plus forte, les changements climatiques avec des événements extrêmes plus fréquents ainsi que la raréfaction des ressources: la qualité du sol se détériore, les terrains destinés aux grandes cultures se réduisent encore d’avantage et l’approvisionnement en eau est toujours plus incertain. Dans ces conditions, une production végétale en Suisse est-elle encore imaginable? Comment permettre le développement d’une production végétale porteuse d’avenir? Des experts de la production végétale se sont posé ces questions sous la direction de la Société suisse d’agronomie (SSA) dans le cadre du projet « Vision production végétale 2050 ». Cette étude a permis de mettre en évidence que seule l’innovation scientifique et technologique dans le domaine de la production végétale peut permettre � l’agriculture d’assurer, même en 2050, les prestations nécessaires � une alimentation de qualité en quantités suffisantes. Et en même temps de supporter la préservation des ressources naturelles telles que l’eau potable, la biodiversité et des paysages attrayants. La SSA révèle les besoins actuels en terme de recherche et de développement, afin de maintenir � long terme une production végétale de qualité en quantités suffisantes. The basic conditions for plant production in Switzerland will have substantially changed by 2050. The main reasons are global and free markets with increased competition, climate change causing more frequently occurring disasters and scarcity of resources: soil quality will diminish, arable land will disappear and water will no longer be constantly available. Is plant production in Switzerland still feasible and expedient under these circumstances? What are the requirements for plant production in the future? Experts in plant sciences addressed these questions during the project “Perspectives for Plant Production 2050” of the Swiss Society of Agronomy (SSA). The conclusions of the study were, that the production of sufficient foods of high quality is only possible based on scientific and technological progress in plant sciences and production. In addition, conservation of fertile agricultural land and public commodities such as recreational landscapes, secure supply of drinking water and conservation of biodiversity are a necessity. The SSA highlights the requirements for research and development for enabling a plant production of high quality and quantity in the future.
Published in: AgrarForschung
Volume: 15
Issue: 7
Pages: 332 - 337
ISSN: 1022-663X
Publication date / Date received: 2008-01-01
Publication status: Bern
Publication status: Published
Subjects: plant production, 2050, perspectives, climate change, scarcity of resources, changed basic conditions
Language: German
Review status: Peer reviewed
Keyword: plant production, 2050, perspectives, climate change, scarcity of resources, changed basic conditions
DBID source: PP-42055, WOS-000257588400006
Nebis system number: 000926925
, Hund, Andreas, Fracheboud, Yvan, Soldati, Alberto, Stamp, Peter, 2008 >>
Author(s): Hund, Andreas, Fracheboud, Yvan, Soldati, Alberto, Stamp, Peter
Title: Cold tolerance of maize seedlings as determined by root morphology and photosynthetic traits
Abstract: Mild chilling stress and slow soil warming are common causes for a retarded early development of maize (Zea mays L.). The objective of this study was to evaluate cold tolerance of a divers set of 14 inbred lines with respect to root morphology as well as the function of the photosynthetic apparatus. Plants were grown until the 2-leaf stage under growth chamber conditions at air and soil temperatures of 15/13 °C and 24/20 °C (day/night). Four contrasting genotypes were tested at 15/13 °C and 17/13 °C (day/night) in the topsoil simulating temperature differences as occurring in no-tillage in comparison with conventional tillage systems. The small variation in the day temperature of 15 °C versus 17 °C in the topsoil affected plant growth and a significant genotype-by-temperature interaction was detected for the chlorophyll content (SPAD) and the operating efficiency of photosystem II (ΦPSII). At 15/13 °C compared to 24/20 °C, differences between genotypes for the primary lateral root (PrLat) length and its portion on the embryonic root system were hardly affected by temperature. ΦPSII and the lateral root length were closest related to plant dry weight at 15/13 °C (r2 = 0.56 and 0.75, respectively), the axile root length and the leaf area were closest related to plant dry weight at 24/20 °C (r2 = 0.46 and 0.83, respectively). Therefore, the selection for long PrLat roots holds promise for the improvement of early vigour in environments and cropping systems with reduced soil warming in spring but might be disadvantageous under warmer conditions.
Published in: European Journal of Agronomy
Volume: 28
Issue: 3
Pages: 178 - 185
ISSN: 1161-0301
Publication date / Date received: 2008-01-01
Publication status: Amsterdam
Publication status: Published
Subjects: Chlorophyll content, Chlorophyll fluorescence, Cold tolerance, Corn, Chilling, Root morphology, Primary root, Seminal root, Soil temperature, Zea mays
Language: English
Review status: Peer reviewed
Keyword: Chlorophyll content, Chlorophyll fluorescence, Cold tolerance, Corn, Chilling, Root morphology, Primary root, Seminal root, Soil temperature, Zea mays
DBID source: PP-42054
DOI: 10.1016/j.eja.2007.07.003
Nebis system number: 000650747
, Hiltbrunner, Jürg, Liedgens, Markus, 2008 >>
Author(s): Hiltbrunner, Jürg, Liedgens, Markus
Title: Performance of winter wheat varieties in white clover living mulch
Published in: Biological agriculture & horticulture : BAH : an international journal for sustainable production systems
Issue: 26
Pages: 85 - 101
ISSN: 0144-8765
Publication date / Date received: 2008-01-01
Publication status: Berkhamsted
Publication status: Published
Language: English
Review status: Peer reviewed
DBID source: PP-42053
Nebis system number: 000017328
, Gobaa, Samy, Bancel, Emmanuelle, Branlard, Gérard, Kleijer, Geert, Stamp, Peter, 2008 >>
Author(s): Gobaa, Samy, Bancel, Emmanuelle, Branlard, Gérard, Kleijer, Geert, Stamp, Peter
Title: Proteomic analysis of wheat recombinant inbred lines: Variations in prolamin and dough rheology.
Abstract: To investigate the impact of the 1BL.1RS translocation on dough strength and to understand how 1BL.1RS genotypes may overcome the loss of Glu-B3 and Gli-B1, proteomic profiles of 16 doubled haploid (DH) lines of similar glutenin composition but of different strength, as measured by Chopin's alveograph, were compared. The results showed that 32 spots, mainly prolamins, were differentially expressed and that five others were specific to high-strength DH lines. The identification and quantification of the prolamin fractions on the two-dimensional (2D) electrophoresis gels demonstrated that the high-molecular weight glutenin sub-unit (HMW-GS) were up-regulated by 25% in 1BL.1RS DH lines, even though the corresponding genes were not located on the missing 1BS chromosome. The γ-gliadins were also up-regulated (by 36%) in such lines to counterbalance, to some extent, the loss of LMW-GS of Glu-B3. The polymeric prolamin fractions also accumulated in high-tenacity lines and decreased in high-extensibility lines confirming the role of the inter-chain disulfide bonds in resistance to deformation. In contrast, the monomeric fraction of α-gliadin favored extensibility and decreased tenacity by increasing the accumulation (+12%) of α-gliadins in high-extensibility lines; the Gli-A1 allele of the parent Toronit was found to be more abundant when compared to the Gli-A1 allele of parent 211.12014.
Published in: Journal of Cereal Science
Volume: 47
Issue: 3
Pages: 610 - 619
ISSN: 0733-5210
Publication date / Date received: 2008-01-01
Publication status: Amsterdam
Publication status: Published
Subjects: Landwirtschaft allgemein|Agriculture, General, Wheat, Proteome, Prolamins, Alveograph, Bread-making quality
Language: English
Review status: Peer reviewed
Keyword: Wheat, Proteome, Prolamins, Alveograph, Bread-making quality
DBID source: PP-42052, WOS-000256601200024
DOI: 10.1016/j.jcs.2007.07.001
Nebis system number: 000021083
, Eschholz, Tobias W., Peter, Roland, Stamp, Peter, Hund, Andreas, 2008 >>
Author(s): Eschholz, Tobias W., Peter, Roland, Stamp, Peter, Hund, Andreas
Title: Genetic diversity of Swiss maize (Zea mays L. ssp. mays) assessed with individuals and bulks on agarose gels
Abstract: About 65 years ago, more than 150 Swiss maize landraces (Zea mays L. ssp. mays) of the flint type were collected and conserved ex situ. Due to the climatically and culturally diverse environment of the Alps, a considerable genetic diversity of this material was assumed. To prove this, an efficient method was required to carry out genetic profiling of all the accessions in the Swiss Gene Bank. Simple sequence repeat marker (SSR) profiling in combination with the visualization of the polymerase chain reaction (PCR) products on agarose gels was chosen. Here a set of 19 different landrace accessions was analyzed to: (i) investigate their genetic diversity, (ii) investigate and display the population structure and (iii) determine whether DNA bulks rather than single plants can be used for such analyses. Four repeated samples of one accession were found to be much closer to one another than to the rest of accessions. Furthermore, specific alleles were identified for several accessions. The PCR products of the bulked DNA samples represented only a small part of the variation revealed by the analysis of individuals. Loci with four base repeat motifs performed better in the analysis of bulks than loci with other repeat motifs. The correlation between genetic distance matrices, based on the analysis of individuals and bulks, respectively, was significant. Thus, the single plant approach allowed for sufficient differentiation of accessions, and DNA bulks visualized on agarose gels led to correlated genetic distances although a limited number of alleles were detected. Although the limited resolution of agarose gels likely causes some bias, profiling of larger sets with the individual plant approach appears feasible and more informative compared to the bulk analysis we conducted.
Published in: Genetic resources and crop evolution
Volume: 55
Issue: 7
Pages: 971 - 983
ISSN: 0925-9864, 1573-5109
Publication date / Date received: 2008-01-01
Publication status: Berlin
Publication status: Published
Subjects: Agarose gels, Bulk analysis, Genetic distance, Flint maize (Zea mays L. ssp. mays), Landraces, SSR profiling
Language: English
Review status: Peer reviewed
Keyword: Agarose gels, Bulk analysis, Genetic distance, Flint maize (Zea mays L. ssp. mays), Landraces, SSR profiling
DBID source: PP-42051
DOI: 10.1007/s10722-007-9304-8
Nebis system number: 000695663
, Bannert, Michael, Vogler, André, Stamp, Peter, 2008 >>
Author(s): Bannert, Michael, Vogler, André, Stamp, Peter
Title: Short-distance cross-pollination of maize in a small-field landscape as monitored by grain color markers
Abstract: Results of studies on cross-pollination in small field environments with regard to donor/receptor surface ratios and flower synchrony are scarce. In 2003 and 2004, six field experiments on cross-pollination were carried out in the cantons of Zug and Zurich, two hilly regions of Switzerland. Three (Monopol, Romario and PR39G12) color-dominant yellow-grain maize varieties (Zea mays L.) were planted in close proximity (0.8 m) to color-recessive white-grain maize (DSP17007). The factors of influence were size of the donor and receptor parts of the field and flower synchrony, tested in a tight grid pattern (2.4 m × 10 m; 6000 ears ha−1). Widely varying field size ratios of donors to receptors (about 4:1–1:8) did not influence the cross-pollination rate at distances of 0–20 m from the pollen donor. The synchrony between pollen shedding of the donor and silking of the receptor had a large impact on cross-pollination. In relation to the mid-phase of silk emergence in the receptor field, a temporal isolation of five and seven days resulted in a significant decrease in cross-pollination by more than 80% in comparison to full synchrony. However, in a receptor field with irregular emergence of a number of weak, late-flowering plants led to a remarkable increase in cross-pollination, despite an average temporal separation of 7 days. Marked cross-pollination was restricted to distances up to 15 m; thus, average rates of cross-pollination above 0.9% were easily managed in small fields.
Published in: European Journal of Agronomy
Volume: 29
Issue: 1
Pages: 29 - 32
ISSN: 1161-0301
Publication date / Date received: 2008-01-01
Publication status: Amsterdam
Publication status: Published
Subjects: Coexistence, Pollen dispersal, Short-distance cross-pollination, Color marker
Language: English
Review status: Peer reviewed
Keyword: Coexistence, Pollen dispersal, Short-distance cross-pollination, Color marker
DBID source: PP-42050, WOS-000257187100004
DOI: 10.1016/j.eja.2008.02.002
Nebis system number: 000650747
, Ribaut, Jean-Marcel, Fracheboud, Yvan, Monneveux, Philippe, Bänziger, Marianne, Vargas, Mateo, Jiang, Changjian, 2007 >>
Author(s): Ribaut, Jean-Marcel, Fracheboud, Yvan, Monneveux, Philippe, Bänziger, Marianne, Vargas, Mateo, Jiang, Changjian
Title: Quantitative trait loci for yield and correlated traits under high and low soil nitrogen conditions in tropical maize
Abstract: The first objective of this study was to map and characterize quantitative trait loci (QTL) for grain yield (GY) and for secondary traits under varying nitrogen (N) supply. To achieve this objective, a segregating F2:3 population previously developed for QTL mapping under water-limited conditions was used. The population was evaluated in Mexico under low N conditions in the dry winter season and under low and high N conditions in the wet summer season. From eight QTLs identified for GY under low N conditions, two were also detected under high N conditions. Five QTLs were stable across the two low N environments and five co-localized with QTLs identified for the anthesis-silking interval (ASI) or for the number of ears per plant (ENO) under low N conditions. The percentage of the phenotypic variance expressed by all QTLs for ASI and ENO was quite different when evaluated under low N conditions during the dry winter (40% for ASI and 22% for ENO) and the wet summer seasons (22% for ASI and 46% for ENO). The results suggest optimizing different breeding strategies based on selection index depending on the growing season. Good QTL colocalization was observed for ASI (four QTLs) and ENO (three QTLs) when looking at QTL identified under low N and water-limited conditions in the same population. The results suggest that that both secondary traits can be used in breeding programs for simultaneous improvement of maize against low N and drought stresses.
Published in: Molecular breeding
Volume: 20
Issue: 1
Pages: 15 - 29
ISSN: 1380-3743, 1572-9788
Publication date / Date received: 2007-01-01
Publication status: Berlin
Publication status: Published
Subjects: Drought tolerance, Low nitrogen tolerance, QTL mapping, Zea mays L
Language: English
Review status: Peer reviewed
Keyword: Drought tolerance, Low nitrogen tolerance, QTL mapping, Zea mays L
DBID source: PP-36178, WOS-000246112100002
DOI: 10.1007/s11032-006-9041-2
Nebis system number: 001430119
, Hund, Andreas, Richner, Walter, Soldati, Alberto, Fracheboud, Yvan, Stamp, Peter, 2007 >>
Author(s): Hund, Andreas, Richner, Walter, Soldati, Alberto, Fracheboud, Yvan, Stamp, Peter
Title: Root morphology and photosynthetic performance of maize inbred lines at low temperature
Abstract: At low temperature, as occurs in the spring, a high photosynthetic performance of maize (Zea mays L.) in combination with a large leaf area is an important measure for early vigor. However, little is known about adaptation of root morphology to low-temperature conditions. The objectives were (i) to characterize a set of 21 modern inbred lines for photosynthesis-related traits and root morphology at 15/13 °C (day/night) and (ii) elucidate relationships between shoot and root traits. Plants were grown in sand substrate until the two-leaf (V2) stage; the operating efficiency of photosystem II (ΦPSII), chlorophyll content (SPAD), and leaf area were used to estimate the rate of CO2 assimilation per plant (). The genotypes were separated as follows: those that maximize leaf area and those that maximize ΦPSII. The morphological organization of the root systems of the genotypes varied to a great extent. Using a principal component analysis (PCA) of root traits (i.e. length of the primary, seminal, and crown roots), genotypes with homogeneous (similar primary and seminal roots) and heterogeneous (lateral roots of the primary root generally longer than the lateral roots of the seminal roots) root systems were identified. The length of the primary lateral roots was most closely associated with all -related traits and with high plant dry weight. Therefore, most of the genotypes with an heterogeneous root system outperformed those with an homogeneous root system with regard to dry matter accumulation and photosynthetic performance. In conclusion, differences in the organization of the embryonic root system are associated with early vigor.
Published in: European journal of agronomy
Volume: 27
Issue: 1
Pages: 52 - 61
ISSN: 1161-0301
Publication date / Date received: 2007-01-01
Publication status: Amsterdam
Publication status: Published
Subjects: Root morphology, Chilling stress, Chlorophyll fluorescence, Zea mays
Language: English
Review status: Peer reviewed
Keyword: Root morphology, Chilling stress, Chlorophyll fluorescence, Zea mays
DBID source: PP-36176, WOS-000247479400006
DOI: 10.1016/j.eja.2007.01.003
Nebis system number: 000650747
, Hiltbrunner, Jürg, Liedgens, Markus, Bloch, Lucia, Stamp, Peter, Streit, Bernhard, 2007 >>
Author(s): Hiltbrunner, Jürg, Liedgens, Markus, Bloch, Lucia, Stamp, Peter, Streit, Bernhard
Title: Legume cover crops as living mulches for winter wheat
Subtitle: Components of biomass and the control of weeds
Abstract: To gain information about the possible use of legume cover crops as an alternative and sustainable weed-control strategy for winter wheat (Triticum aestivum L.), an experiment was conducted at two sites in the Swiss Midlands in 2001/2002. Under organic farming conditions winter wheat was direct-drilled into living mulches established with four different legume genotypes or into control plots without cover crops. Compared to NAT (control plots without cover crops but with a naturally establishing weed community), white clover (Trifolium repens L.), subclover (Trifolium subterraneum L.), and birdsfoot trefoil (Lotus corniculatus L.) reduced the density of monocotyledonous, dicotyledonous, spring-germinating, and annual weeds by the time of wheat anthesis. Strong-spined medick (Medicago truncatula Gaertner) was less efficient in this regard. While the grain yield was reduced by 60% or more for all legumes when compared to NOWEED (control plots kept weed-free), a significant negative correlation between the dry matter of the cover crop and weeds as well as between the cover crop and the winter wheat was observed by the time of wheat anthesis. The effect of manuring (60 m3 ha−1 liquid farmyard manure) was marginal for weeds and cover crops but the additional nutrients significantly increased total winter wheat dry matter and grain yields. The suppression achieved by some legumes clearly demonstrates their potential for the control of weeds in such cropping systems. However, before living legume cover crops can be considered a viable alternative for integrated weed management under organic farming conditions, management strategies need to be identified which maximise the positive effect in terms of weed control at the same time as they minimise the negative impact on growth and yield of winter wheat.
Published in: European journal of agronomy
Volume: 26
Issue: 1
Pages: 21 - 29
ISSN: 1161-0301
Publication date / Date received: 2007-01-01
Publication status: Amsterdam
Publication status: Published
Subjects: Cover crop, Legume, Living mulch, Organic farming, Weed, Winter wheat
Language: English
Review status: Peer reviewed
Keyword: Cover crop, Legume, Living mulch, Organic farming, Weed, Winter wheat
DBID source: PP-36168, WOS-000243293700003
DOI: 10.1016/j.eja.2006.08.002
Nebis system number: 000650747
, Hiltbrunner, J., Streit, B., Liedgens, M., 2007 >>
Author(s): Hiltbrunner, J., Streit, B., Liedgens, M.
Title: Are seeding densities an opportunity to increase grain yield of winter wheat in a living mulch of white clover?
Abstract: Optimum plant densities are a key to maximise yields in most crops. However, such information is often lacking for more environmentally sound cropping systems, such as living mulches (LM) for small grains. In 2004 and 2005, three trials were conducted in the Swiss Midlands on fields managed in accordance with the Swiss organic farming guidelines. The objective of the study was to determine whether seeding density of winter wheat (Triticum aestivum L.) is a relevant factor for determining grain yield in a white clover (Trifolium repens L.) living mulch. The winter wheat cv. Titlis was directly sown in wide spaced rows (0.375 m) at densities of 300 (LM300), 450 (LM450) or 600 (LM600) viable grains m−2 in a white clover living mulch established at a seeding rate of 15 kg ha−1. A bare soil control treatment with a wheat density of 450 viable grains m−2 (BS450) was also included in the trials. Mean grain yields of LM300, LM450, and LM600 never reached the values observed in BS450. This was mainly due to a lower ear density, which, nevertheless, increased linearly with the seeding density within the living mulch in all trials, but the rate of increase depended on the environment. The decrease of the grain weight brought about by the increasing seeding density had only a marginal impact on the grain yield, which was increased from 1.31, 1.98, and 4.09 Mg ha−1 (LM300) to 1.97, 2.64, and 4.75 Mg ha−1 (LM600) for each of the three trials in the study. Significantly higher protein contents were observed for LM300 compared to the higher densities in the living mulch and to BS450. Our research showed that an increase of the seeding density is an effective mean to increase the grain yield in living mulch systems with white clover. However, it is likely that the control of the living mulch to reduce competition with the main crop is a more relevant factor.
Published in: Field crops research
Volume: 102
Issue: 3
Pages: 163 - 171
ISSN: 0378-4290
Publication date / Date received: 2007-01-01
Publication status: Amsterdam
Publication status: Published
Subjects: Landwirtschaft allgemein|Agriculture, General, Winter wheat, Triticum aestivum L., White clover, Trifolium repens L., Living mulch, Yield components, Organic farming
Language: English
Review status: Peer reviewed
Keyword: Winter wheat, Triticum aestivum L., White clover, Trifolium repens L., Living mulch, Yield components, Organic farming
DBID source: PP-36174, WOS-000247409500001
DOI: 10.1016/j.fcr.2007.03.009
Nebis system number: 000002745
, Hiltbrunner, J., Jeanneret, P., Liedgens, M., Stamp, P., Streit, B., 2007 >>
Author(s): Hiltbrunner, J., Jeanneret, P., Liedgens, M., Stamp, P., Streit, B.
Title: Response of weed communities to legume living mulches in winter wheat
Abstract: In order to obtain information about the impact of legume cover crops on the weed community in organic farming, winter wheat (Triticum aestivum L.) was directly drilled in rows 0.1875 and 0.3750 m apart in living mulches that consisted of Trifolium repens L. (TRFRE), T. subterraneum L. (TRFSU), Medicago truncatula Gaertner (MEDTR), and Lotus corniculatus L. (LOTCO). A control treatment without cover crops (NAT, the site-specific weed community) was also established. The vegetation between the wide rows was either mulched or left undisturbed. The effect of liquid farmyard manure (60 m3 ha−1) was also tested. TRFRE, TRFSU, and LOTCO effectively suppressed Poa annua L. and Matricaria recutita L. at site 1 and P. annua, Capsella bursa-pastoris (L.) Med., and Stellaria media (L.) Vill. at site 2 when compared with NAT. MEDTR, which died during the winter, provided little weed suppression. Mulching significantly suppressed dicotyledonous weed species, but favoured Poa trivialis L. No manure effect was observed. Winter hardy legume cover crops contribute to weed suppression in winter wheat. However, careful evaluation of cover crop × weed × management interactions is necessary to understand the risk for the establishment of problematic weeds.
Published in: Journal of agronomy and crop science
Volume: 193
Issue: 2
Pages: 93 - 102
ISSN: 0931-2250, 0044-2151, 1439-037X
Publication date / Date received: 2007-01-01
Publication status: Berlin
Publication status: Published
Subjects: legumes, living mulch, multivariate analysis, organic farming, weed community, winter wheat
Language: English
Review status: Peer reviewed
Keyword: legumes, living mulch, multivariate analysis, organic farming, weed community, winter wheat
DBID source: PP-36166
DOI: 10.1111/j.1439-037X.2007.00250.x
Nebis system number: 000033963
, Herrera, Juan M., Stamp, Peter, Liedgens, Markus, 2007 >>
Author(s): Herrera, Juan M., Stamp, Peter, Liedgens, Markus
Title: Interannual variability in root growth of spring wheat (Triticum aestivum L.) at low and high nitrogen supply
Abstract: Little is known about the spatial and temporal characteristics of the root growth of spring wheat and its modification by nitrogen (N) supply. For 4 years the cultivar Toronit was fertilized with 20 (LN) or 270 kg N ha−1 (HN) in lysimeters. The shoot traits were measured at harvest, while root growth was screened regularly at 10 soil depths in minirhizotrons between 0.05 and 1.00 m. The cumulative number of roots cm−2 (CNR) was fitted to a logistic equation to study the course of root growth at each soil depth. Furthermore, the vertical patterns of CNR were examined at the beginning of tillering, stem elongation, anthesis and physiological maturity by a non-parametric regression (splines). The parameters of the logistic and non-parametric models were influenced by all the factors; thus the root system was highly plastic. Whereas the N off take was similar at LN in 1999, 2001 and 2002, the period of linear increase in CNR in the subsoil was 7 d longer in 2001 than in 2002. At HN, the N off take was higher in 1999 than in 2001 but the reverse was true for root growth. There was also variation among years in the total duration of root growth, with differences up to 20 d. The percentage of roots grown after anthesis ranged from 1 to 22% of the total roots grown by physiological maturity, demonstrating that the root growth of spring wheat can be high and variable after anthesis. This percentage differed among years more in the subsoil and supported the evidence provided by the time parameters of the logistic equation that the impact of climatic and soil conditions on root growth seems to become stronger with time. At all levels of N supply, the vertical pattern of CNR was characterized by an exponential decrease at the beginning of tillering in all the years. Such a clear pattern was not found at later developmental stages. Though the basic knowledge of the variability of root growth of spring wheat increased, the interannual variability in root dynamics was not explained fully by climatic differences among the growing seasons.
Published in: European journal of agronomy
Volume: 26
Issue: 3
Pages: 317 - 326
ISSN: 1161-0301
Publication date / Date received: 2007-01-01
Publication status: Amsterdam
Publication status: Published
Subjects: Landwirtschaft allgemein|Agriculture, General, Wheat, Nitrogen, Root, Development, Growth, Soil
Language: English
Review status: Peer reviewed
Keyword: Wheat, Nitrogen, Root, Development, Growth, Soil
DBID source: PP-36165, WOS-000245623900015
DOI: 10.1016/j.eja.2006.11.003
Nebis system number: 000650747
, Herrera, J. M., Stamp, P., Liedgens, M., 2007 >>
Author(s): Herrera, J. M., Stamp, P., Liedgens, M.
Title: Dynamics of root development of spring wheat genotypes varying in nitrogen use efficiency
Abstract: Three spring wheat genotypes (cv. Albis and Toronit and the experimental line L94491) identified to vary in nitrogen use efficiency characteristics, were studied in lysimeters under two levels of N supply (0 and 250 Kg N ha-1) in 1999 and 2000. No. of roots cm-2 were obtained from regular minirhizotron observations at soil depths of 0.10, 0.25, 0.45, 0.80 and 1.00 m and fitted to a logistic equation. The parameters of the logistic model were influenced by all study factors, indicating a high plasticity of the root system of spring wheat to respond to different soil conditions. A single main genotype effect was observed among all tested factors: the asymptotic no. of roots cm-2 was significantly higher for Toronit than Albis and especially L94491 in the topsoil (0.10 and 0.30 m). Contrastingly, the N supply modified the asymptotic growth in 1999 at 0.10 m and in both years at 0.25 m as well as the root growth pattern at 0.80 in 1999 and at 0.10 m and 0.25 m soil depth in both years.
Book title: Wheat Production in Stressed Environments : proceedings of the 7th International Wheat Conference, 27 November-2 December 2005, Mar del Plata, Argentina
Published in: Developments in plant breeding
Volume: 12
Pages: 197 - 201
ISBN: 978-1-4020-5496-9, 978-1-4020-5497-6, 1-4020-5496-3
Publication date / Date received: 2007-01-01
Publication status: Berlin
Publication status: Published
Subjects: Acker- und Futterbau (inkl. Kultur- und Nutzpflanzen) | Crop and Fodder Farming (incl. Cultivated and Crop Plants), root development, nitrogen
Event name: 7th International Wheat Conference (7 IWC)
Event date: November 27 - December 2, 2005
Place: Mar del Plata, Argentina
Language: English
Review status: Peer reviewed
Keyword: root development, nitrogen
DBID source: PP-36164
DOI: 10.1007/1-4020-5497-1_25
Nebis system number: 005427717
, Gobaa, Samy, Bancel, Emmanuelle, Kleijer, Geert, Stamp, Peter, Branlard, Gerard, 2007 >>
Author(s): Gobaa, Samy, Bancel, Emmanuelle, Kleijer, Geert, Stamp, Peter, Branlard, Gerard
Title: Effect of the 1BL.1RS translocation on the wheat endosperm, as revealed by proteomic analysis
Abstract: The introduction of the 1RS chromosome of rye into wheat made wheat more resistant to several pathogens. Today, this resistance has been overcome but the 1BL.1RS translocation remains interesting because of the improved yield and despite the lower rheological properties it produces. Nothing has been reported yet on the impact of rye chromatin introgression on the grain proteome of wheat. The comparison of the 2-DE profiles of 16 doubled haploid lines, with or without the 1BL.1RS translocation, revealed quantitative and qualitative proteic variations in prolamins and other endosperm. proteins. Eight spots were found specifically in lines having the 1BL.1RS translocation; 16 other spots disappeared from the same lines. Twelve spots, present in both genotypes, met the criteria for up- or down-regulated spots. In translocated genotypes, a highly overexpressed spot, identified as a gamma-gliadin with nine cysteine residues, suggests that the lack of LMW-GS induced by 1BL.1RS is counterbalanced by an overexpression of a relatively similar prolamin. Moreover, a spot that was absent from 1BL.1RS genotypes was identified as a dimeric alpha-amylase inhibitor. It was considered to be a valuable candidate to explain the sticky dough associated with translocated cultivars.
Published in: Proteomics
Volume: 7
Issue: 23
Pages: 4349 - 4357
ISSN: 1615-9853, 1615-9861
Publication date / Date received: 2007-01-01
Publication status: Weinheim
Publication status: Published
Subjects: 1BL.1RS translocation, prolamins, wheat
Language: English
Review status: Peer reviewed
Keyword: 1BL.1RS translocation, prolamins, wheat
DBID source: PP-36157
DOI: 10.1002/pmic.200700488
Nebis system number: 004185633
, Gobaa, S., Kleijer, G., Stamp, P., 2007 >>
Author(s): Gobaa, S., Kleijer, G., Stamp, P.
Title: 2.., a new high molecular weight glutenin subunit coded by Glu-A1
Subtitle: Its predicted structure and its impact on bread-making quality
Abstract: The suitability of wheat varieties for bread-making depends on their glutenin subunits. The amino acid composition of these gluten building-blocks have a strong influence on the rheology of the dough and, thus, on the suitability of the variety for bread-making. This study reports a new x-type high molecular weight glutenin subunit coded by the locus Glu-A1 and named 2 center dot center dot. To investigate the impact of this allele on 10 quality parameters, a doubled haploid (DH) population of Triticum aestivum, segregating for Glu-A1, was created. The statistical analysis demonstrates that, at Glu-A1, the subunit 2 center dot center dot is as favourable for quality as the subunit 2*. This is in accordance with results showing that the 2 center dot center dot open reading frame still has the same number of cysteines as 2*. The small differences in the length of the central domain had no detectable effect on the elasticity, tenacity and baking quality, of the dough.
Published in: Plant breeding
Volume: 126
Issue: 1
Pages: 1 - 4
ISSN: 0179-9541, 1439-0523
Publication date / Date received: 2007-01-01
Publication status: Berlin
Publication status: Published
Subjects: Triticum aestivum, glutenin, Glu-A1, allele, Ax2.., bread-making quality
Language: English
Review status: Peer reviewed
Keyword: Triticum aestivum, glutenin, Glu-A1, allele, Ax2.., bread-making quality
DBID source: PP-36162, WOS-000243974800001
DOI: 10.1111/j.1439-0523.2006.01313.x
Nebis system number: 000034603
, Fournier, J. M., Stamp, P., Bolaños, J., 2007 >>
Author(s): Fournier, J. M., Stamp, P., Bolaños, J.
Title: The Technological Gap for Maize Cultivation and Soil Properties in a Watershed of Guatemala
Abstract: The technological gap is wide between potential and actual maize yields in the tropics. An estimation and explanation of the existing yield gap in a model region of Guatemala were attempted. Experiments were carried out on the hypothesis that soil constraints like lack of nutrients exist on 74 farms in four seasons from 1996 to 1998. The hybrid HB-83 was compared with local varieties. Treatments included no fertilizer or the application of recommended and supra optimum amounts of fertilizers. The P and K availability was low. At the site with the lowest yield potential, HB-83 yielded 65 % more than the local varieties, while at the site with the highest yield potential, this relative yield advantage was only 28 %. However, the absolute yield difference between HB-83 and the local varieties was 70 % higher at the site with the highest yield potential compared with the site with the lowest yield potential, with grain yields ranging from 5.21 to 0.29 t ha−1 for local varieties. There were few significant correlations between soil parameters and plant traits. Plant nutrient constraints besides NPK and liming did not seem to limit the yield potential in the Polochic watershed. A combination of soil management practices, liming in association with corrected levels of P, and use of crop cultivars developed for these low pH conditions could lead to sustainable and productive maize production.
Published in: Journal of agronomy and crop science
Volume: 193
Issue: 6
Pages: 452 - 460
ISSN: 0931-2250, 0044-2151, 1439-037X
Publication date / Date received: 2007-01-01
Publication status: Berlin
Publication status: Published
Subjects: maize, soil properties, technological gap, watershed
Language: English
Review status: Peer reviewed
Keyword: maize, soil properties, technological gap, watershed
DBID source: PP-36156, WOS-000250587000008
DOI: 10.1111/j.1439-037X.2007.00275.x
Nebis system number: 000033963
, Bannert, Michael, Stamp, Peter, 2007 >>
Author(s): Bannert, Michael, Stamp, Peter
Title: Cross-pollination of maize at long distance
Abstract: In a 2-year-study in Switzerland the cross-pollination of maize was investigated by using the occurrence of yellow grains in 13 white grain maize fields as a marker of cross-pollination from neighbouring yellow grain fields. Distances of 50-4500 m between pollen-donor and pollen-receptor fields were investigated. In no case, the cross-pollination of the whole field was more than 0.02%. Four white grain maize fields, located in downwind distances of 50-371 m in the main wind direction, showed low but marked cross-pollination at the field border exposed to the nearest yellow grain maize field. In every field some cross-pollinations with a low rate, on an average of 1.8% of the sampled ears, could be found. These cross-pollinations were mainly single cross-pollinations on the ear. Horizontal wind speed measurements during flowering time in relation to the settling speed of maize pollen showed a potential horizontal pollen dispersal distance of up to 55 m. The few observed cross-pollinations over longer distances could be due to gusts or vertical movements of the wind (e.g., thermal or turbulence effects). In some fields spots of higher cross-pollinations were found. In the cases where the surrounding plants were checked a yellow grain maize seed contamination (0.004% of the seedstock) in the white seeds could be determined as the reason for these "hot-spots".
Published in: European journal of agronomy : the official journal of the European Society for Agronomy
Volume: 27
Issue: 1
Pages: 44 - 51
ISSN: 1161-0301
Publication date / Date received: 2007-01-01
Publication status: Amsterdam
Publication status: Published
Subjects: Cross-pollination, Coexistence, Pollen dispersal, Colour marker, Maize
Language: English
Review status: Peer reviewed
Keyword: Cross-pollination, Coexistence, Pollen dispersal, Colour marker, Maize
DBID source: PP-36154, WOS-000247479400005
DOI: 10.1016/j.eja.2007.01.002
Nebis system number: 000650747
, Sangakkara, U.R., Stamp, P., 2006 >>
Author(s): Sangakkara, U.R., Stamp, P.
Title: Influence of different weed categories on growth and yields of maize ( Zea mays ) grown in a minor (dry) season of the humid tropics
Abstract: Weed control is an important management practice in smallholder tropical upland farming systems, and manual weeding is a common feature in these units. This makes selective weeding possible, which is an essential component of integrated weed management. Field studies were initiated in Sri Lanka over a minor (dry) season to determine the impact of different weeds (grasses, broadleaves and sedges) and nonweeded conditions on the growth and yields of maize, cultivated under rainfed conditions. Weed populations were also determined, along with root distribution of the different weed management regimes at anthesis of maize. The presence of all types of weeds or grasses, which was the most dominant weed category, had the greatest adverse impact on growth and yields of maize. The reductions in seed yield due to the presence of all weeds or grasses alone were 59% and 32%, respectively. In contrast, growth and yields of maize was not affected by the small numbers of sedges present. The impact of broadleaved species was lower than that of all weeds or the grasses. Root distribution through the soil profile was greatest when maize was grown with broadleaved species or with all weeds. The roots of the maize-grass mixtures were concentrated in the upper soil layers. The beneficial impact of removing grasses and broadleaved weeds in selective manual weeding in rainfed maize cultivation which could be practiced by smallholder farming units to obtain higher yields are presented. Die Kontrolle von Schadpflanzen gehört zu den wichtigen Tätigkeiten im kleinbäuerlichen Landbau tropischer ochlandregionen und das Jäten ist eine verbreitete Praktik auf solchen Betrieben. Jäten ermöglicht ein selektives Entfernen der Schadpflanzen und gehört zu den essenziellen Bestandteilen einer integrierten Schadpflanzenbekämpfung. Auf Sri Lanka wurden Feldversuche während der Trockenzeit durchgeführt, um den Einfluss verschiedener Schadpflanzengruppen (Gräser, breitblättrige Schadpflanzen und Seggen) und unbehandelter Felder auf den Ertrag von Mais im Regenfeldbau zu bestimmen. Schadpflanzenpopulationen wurden zusammen mit der Wurzelverteilung im Bodenprofil zu Beginn der Maisblüte in den verschiedenen Behandlungsvarianten bestimmt. Das gemeinsame Vorkommen aller Gruppen dikotyler Schadpflanzen und Gräser, die die dominante Gruppe darstellten, hatte den größten negativen Einfluss auf Wachstum und Ertrag von Mais. Die Ertragsverluste beim gemeinsamen Vorkommen aller Schadpflanzengruppen oder nur der Gräser betrugen 59 bzw. 32%. Die in geringer Zahl vorkommenden Seggen verringerten den Ertrag dagegen nicht. Der Einfluss breitblättriger Schadpflanzen war geringer als der der Gräser oder der aller Gruppen gemeinsam. Die urzelverteilung im Bodenprofil war am ausgeprägtesten in Gegenwart von allen Pflanzengruppen gemeinsam oder der breitblättrigen Pflanzen alleine. In ausschließlicher Gegenwart von Schadgräsern wuchsen die Maiswurzeln nur in den obersten Bodenschichten. Die Vorteile einer selektiven Entfernung von Gräsern und breitblättrigen Schadpflanzen, die im kleinbäuerlichen Regenfeldbau von Mais in tropischen Hochlandregionen praktikabel ist, werden dargestellt.
Published in: Journal of plant diseases and protection
Volume: 113
Issue: 2
Pages: 81 - 85
ISSN: 1861-3829, 0340-8159, 1861-3837
Publication date / Date received: 2006-01-01
Publication status: Stuttgart
Publication status: Published
Subjects: Broadleaves, Grasses, Manual weeding, Sedges, Weeds
Language: English
Review status: Peer reviewed
Keyword: Broadleaves, Grasses, Manual weeding, Sedges, Weeds
DBID source: PP-28154, WOS-000238252800006
Nebis system number: 000039466
, Sangakkara, U.R., Stamp, P., 2006 >>
Author(s): Sangakkara, U.R., Stamp, P.
Title: Impact of selective weeding on maize productivity in major and minor seasons
Subtitle: A comparative analysis from the Asian humid tropics
Abstract: Weed management is vital in tropical food cropping systems to minimize competition for scare resources, especially under smallholder farming conditions, where hand weeding using family labor is a common feature. Hence, selective weeding could be practiced to maintain weed populations below economic threshold levels, and minimize competition. Field studies were initiated under rainfed conditions of Sri Lanka over the major and minor seasons that correspond to the two monsoons to determine the impact of selective weeding on growth and yields of maize (Zea mays L), the most popular highland cereal in these regions. The lack of weed control measures or the presence of the most abundant grass weeds reduced growth and yields of maize irrespective of the season. The adverse effects of the low number of sedges (Cyperaceae) was minimal, and that of broadleaves was lower than the impact of grasses. Comparative analysis of the effects of weeds in the two seasons highlighted the greater adverse effect in the minor season when the crop is subjected to water stress conditions. The weed numbers were greater, which affected the growth and yields of maize to a greater extent. However, the adverse effects of the different weed types did not change with seasons. The feasibility of adopting selective weeding to minimize adverse effects in rainfed farming systems of the humid tropics for procuring high yields is presented on the basis of this study. In contrast, clean weeding could develop other effects such as erosion. Eine Unkrautkontrolle in tropischen Anbausystemen zur Nahrungsmittelproduktion ist unerlässlich, um die Konkurrenz um die knappen Ressourcen zu minimieren. Dies gilt besonders unter kleinbäuerlichen Bedingungen, wo das Jäten per Hand noch üblich ist. So kann eine selektive Unkrautvernichtung dazu beitragen, die Unkrautpopulation unterhalb der Schadensschwelle zu halten und so die Konkurrenz zu minimieren. In Feldversuchen ohne Bewässerungssystem in Sri Lanka während der Kleinen und der Großen Regenzeit – die mit den beiden Monsunzeiten übereinstimmen – wurde der Einfluss einer selektiven Unkrautentfernung auf das Wachstum und den Ertrag von Mais (Zea mays L), der häufigsten Getreideart in dieser Bergregion, untersucht. Das Fehlen jeglicher Unkrautkontrollmassnahmen oder der Besatz mit den häufigsten Ungräsern beeinträchtigen sowohl das Wachstum als auch den Ertrag unabhängig von der Anbausaison. Seggen und das Vorkommen von breitblättrigen Unkräutern hatten einen geringeren negativen Einfluss als das Vorkommen von Ungräsern. Vergleichende Analysen der Auswirkungen von Unkräutern auf die Produktivität von Mais in den unterschiedlichen Anbauzeiträumen zeigte einen stärkeren Einfluss in der kleinen Regenzeit, wenn die Pflanze einem Wasserstress ausgesetzt ist. Die Unkrautzahlen waren höher, was zu einer stärkeren Reduktion des Wachstums und des Ertrages von Mais führte. Die spezifischen Einflüsse der verschiedenen Unkrautarten werden durch die Anbausaison jedoch nicht verändert. Die Umsetzbarkeit der selektiven Unkrautkontrolle zur Erreichung eines höheren Ertrags in unbewässerten Anbausystemen der feucht-tropischen Regionen Asiens wird unter Berücksichtigung des Vergleichs mit einer totaler Unkrautvernichtung, die zu anderen unerwünschten Effekten wie z.B. Erosion führen kann, diskutiert.
Published in: Journal of plant diseases and protection. Special Issue
Volume: XX
Pages: 701 - 708
ISSN: 1861-4051
Publication date / Date received: 2006-01-01
Publication status: Stuttgart
Publication status: Published
Subjects: Weeds, selective weeding, maize, major and minor seasons, humid tropics, Unkräuter, selektive Unkrautbekämpfung, Mais, Große und Kleine Regenzeit, feuchte Tropen
Language: English
Review status: Peer reviewed
Keyword: Weeds, selective weeding, maize, major and minor seasons, humid tropics, Unkräuter, selektive Unkrautbekämpfung, Mais, Große und Kleine Regenzeit, feuchte Tropen
DBID source: PP-28161
, Sangakkara, U.R., Bandaranayake, P.R.S.D., Weerasekera, D.N.K., Stamp, P., 2006 >>
Author(s): Sangakkara, U.R., Bandaranayake, P.R.S.D., Weerasekera, D.N.K., Stamp, P.
Title: Interseasonal cropping
Subtitle: Its potential for managing weeds in the Asian tropics
Abstract: Tropical farming systems cultivate food and cash crops with the monsoonal rains. Lands are generally left fallow during the interseasonal periods, thus building up weed populations and weed seed banks. Field studies were conducted to determine the impact of managing the interseasonal periods by growing either a food crop or green manures and its impact on weed populations in the subsequent season. The management strategies used after a maize crop in the major season were leaving the land fallow as normal practice, growing Phaseolus beans (a food crop), Crotalaria juncea (a fast growing legume green manure) or Tithonia diversifolia (a slow growing non legume green manure). A crop of mungbean (Vigna radiata L.) was planted in the following minor season and weed populations were monitored, along with crop yields. As expected, the weed populations in plots left fallow were the highest, thus requiring weeding in the mungbean crop on three occasions. Lack of weeding reduced mung bean seed yields by 67 %, when compared to the weeded plots. Growing Crotalaria juncea as legume cover crop resulted in the lowest weed populations in mungbean, thus requiring only one weeding, and the lack of weeding reduced yields only by 18 % as compared to the weeded plots. The slower growing green manure (Tithonia diversifolia ) or the food crop (beans) facilitated a greater population of weeds in the succeeding mungbean crop. The importance of managing the interseasonal fallow periods for better integrated weed management strategies of smallholder tropical farming systems is discussed. In den Tropen werden Nahrungs- und Handelspflanzen während der Regenzeit angebaut. Das Land liegt in der Trockenzeit meist brach und Unkrautpopulationen können sich etablieren und aussamen. In Feldversuchen wurde getestet, welchen Einfluss der Anbau entweder einer Nahrungspflanze oder von Gründüngungspflanzen in der Trockenzeit auf die Unkrautpopulation in der folgenden Anbauperiode haben. Folgende Massnahmen kamen zum Einsatz: Nach Mais in der Regenzeit wurde das Feld nicht bebaut – wie es übliche Praxis ist – oder mit Phaseolus Bohnen (einer Nahrungspflanze), Crotolaria juncea (eine schnell wachsende Leguminose zur Gründüngung) bzw. Tithonia diversifolia (eine langsam wachsende Gründungsungspflanze, keine Leguminose) bebaut. In der folgenden kleinen Regenzeit wurden Mungbohnen angepflanzt und die Zahl der Unkrautpflanzen erhoben und der Ertrag ermittelt. Wie erwartet war der Unkrautbesatz nach der Brache am höchsten und machte drei Unkrautbekämpfungsmassnahmen notwendig. Ohne Unkrautbekämpfung war der Samenertrag der Mungbohne um 67 % reduziert, verglichen mit den gejäteten Flächen. Der Anbau von Crotolaria juncea, der schnell wachsenenden Leguminose hinterliess die geringste Unkrautpopulation in den Mungbohnenkulturen, die nur ein einmaliges Jäten erforderte. Ohne Unkrautbekämpfung wurde der Ertrag nur um 18 % reduziert verglichen zu den Parzellen mit Jäten. Die langsam wachsende Gründüngungspflanze (Tithonia diversifolia) oder die Phaseolusbohne unterdrückten die Unkrautpopulation in der nachfolgenden Kultur weniger gut Die Bedeutung einer Bewirtschaftung der Landfläche während der Trockenzeit für eine besser integrierte Unkrautkontrolle in kleinbäuerlichen Betrieben der Tropen wird diskutiert.
Published in: Journal of plant diseases and protection
Volume: Special Issue XX
Pages: 921 - 927
ISSN: 1861-3829, 0340-8159, 1861-3837
Publication date / Date received: 2006-01-01
Publication status: Stuttgart
Publication status: Published
Subjects: Tropics, interseasonal fallow periods, weed management, cropping yields, Tropen, Trockenzeitbrache, Unkrautkontrollmassnahmen, Anbausystem, Ertrag
Language: English
Review status: Peer reviewed
Keyword: Tropics, interseasonal fallow periods, weed management, cropping yields, Tropen, Trockenzeitbrache, Unkrautkontrollmassnahmen, Anbausystem, Ertrag
DBID source: PP-28164, WOS-000243269500003
Nebis system number: 000039466
, Qin, Ruijun, Stamp, Peter, Richner, Walter, 2006 >>
Author(s): Qin, Ruijun, Stamp, Peter, Richner, Walter
Title: Impact of tillage on maize rooting in a Cambisol and Luvisol in Switzerland
Abstract: Soil conditions under no-tillage (NT) are often unfavorable for the growth of maize roots in comparison to conventional tillage (CT). In 1997 and 1999, the impacts of tillage on the morphology and spatial distribution of maize (Zea mays L.) roots at anthesis were investigated in a 5-year field trial at two sites (loamy silt and sandy loam soils) in the Swiss midlands. Four soil cores, perpendicular to the maize row, were taken to a depth of 100 cm in each plot; the root length density (RLD), the mean root diameter (MD), and the relative length per diameter-class distribution (LDD) of the roots were determined. Roots were longer and thinner in 1999 than in 1997. The RLD was significantly higher and the MD was smaller on the loamy silt than on the sandy loam. The RLD and MD decreased with the distance from the plant row. Most of the maize roots, about 80% of the total root length, were in the layer from 0 to 40 cm, with maximum values from 5 to 10 cm; the thickest roots were in the soil layer from 10 to 50 cm. Significant differences in RLD with increasing distance from the row of plants were found in the top 30 cm. Averaged over the whole soil profile, RLD was higher and MD was smaller under CT than under NT. The impact of tillage on RLD and MD interacted with spatial factors and years. Within the soil profile, RLD was significantly higher under NT than under CT at a depth of 5 cm, whereas it was higher under CT than under NT below 10 cm. Below 50 cm, there was no difference in RLD between the tillage systems. In a horizontal direction, MD was consistently higher in the row and lower in the mid-row under NT than under CT. Our results show that differences in maize root growth between tillage systems, which were reported in previous studies, persist until anthesis. The accumulation of maize roots near the soil surface in NT suggests that subsurface-banding of starter fertilizer is a more efficient way of applying fertilizer (particularly immobile nutrients such as phosphorus) compared with broadcasting in order to supply sufficient nutrients for NT maize.
Published in: Soil & tillage research
Volume: 85
Issue: 1-2
Pages: 50 - 61
ISSN: 0167-1987
Publication date / Date received: 2006-01-01
Publication status: Amsterdam
Publication status: Published
Subjects: Root morphology, Root distribution, Maize, No-tillage, Conventional tillage
Language: English
Review status: Peer reviewed
Keyword: Root morphology, Root distribution, Maize, No-tillage, Conventional tillage
DBID source: PP-28150, WOS-000234146700005
DOI: 10.1016/j.still.2004.12.003
Nebis system number: 000009865
, Peter, R., Eschholz, T.W., Stamp, P., Liedgens, M., 2006 >>
Author(s): Peter, R., Eschholz, T.W., Stamp, P., Liedgens, M.
Title: Swiss maize landraces
Subtitle: Early vigour adaptation to cool conditions
Abstract: Due to their good early vigour, Swiss maize landraces have been used extensively to develop the Flint Pool of European hybrid-breeding programmes. However, the basis of good early vigour, especially under cool conditions, has not been elucidated. Of 166 pre-screened Swiss maize landraces, 17 contrasting accessions were tested together with two control accessions, a German landrace and a modern hybrid cultivar with proven good early vigour, at sites in the midlands and the foothills of the Alps in Switzerland. To investigate early vigour, photosynthesis, leaf greenness and plant growth were recorded. Compared to the modern standard hybrid cultivar, northern accessions showed superior early vigour under cold stress in the field for all traits examined in these experiments, whereas these traits were much less pronounced in southern accessions. In particular, some accessions from the Rhine valley seem to be promising sources of early vigour for use in breeding programmes. These findings support the hypothesis that long-term selection resulted in the adaptation of maize landraces to their local environment. Compared to the phylogenetic tree, it is evident that accessions with superior early vigour are related to each other and originated in the Rhine valley.
Published in: Acta agronomica Hungarica
Volume: 54
Issue: 3
Pages: 329 - 336
ISSN: 1588-2527, 0238-0161
Publication date / Date received: 2006-01-01
Publication status: Budapest
Publication status: Published
Subjects: flint maize, Zea mays L., cold tolerance, landraces, early vigour
Language: English
Review status: Peer reviewed
Keyword: flint maize, Zea mays L., cold tolerance, landraces, early vigour
DBID source: PP-28145
DOI: 10.1556/AAgr.54.2006.3.7
, Moser, Samuel B., Feil, Boy, Jampatong, Sansern, Stamp, Peter, 2006 >>
Author(s): Moser, Samuel B., Feil, Boy, Jampatong, Sansern, Stamp, Peter
Title: Effects of pre-anthesis drought, nitrogen fertilizer rate, and variety on grain yield, yield components, and harvest index of tropical maize
Abstract: Water and nitrogen (N) are the most limiting factors for grain yield of maize (Zea mays L.) in the tropics. In Thailand, the risk of water shortage is highest during the vegetative stages of maize development. A 3-year study with two water regimes (pre-anthesis drought versus irrigation throughout the vegetation cycle), three levels of N fertilization (0, 80, and 160 kg N ha−1), two open-pollinated varieties (Suwan 1 and La Posta Sequia), and two hybrids (KTX2602 and DK888) was conducted to determine the interactive effects of pre-anthesis water supply, N fertilizer rate, and variety on the grain yield, yield components, and harvest index of maize in the tropical lowlands of Thailand. Averaged across the N rates and varieties, drought-stressed maize yielded 32% (1995), 13% (1996), and 21% (1997) less than well-watered maize. Irrespective of variety, 80 kg N ha−1 was sufficient to achieve maximum grain yield under pre-anthesis drought, whereas 160 kg N ha−1 resulted in the highest yield under well-watered conditions. Pre-anthesis drought significantly reduced the number of kernel rows, the number of kernels per row, as well as the 1000-kernel weight. The effect of the water regime on the ear number of DK888 varied from year-to-year. Water stress consistently resulted in increases in the harvest index. There were significant effects of the water regime × variety interaction on grain yield in two of the three cropping seasons. KTX2602 was more affected by drought than Suwan 1 in all the years and, in 2 of the 3 years, than La Posta Sequia. This was attributed to the fact that KTX2602 was the earliest variety. In 1996, DK888, the top yielder, produced almost the same grain yield under drought stress and continuous irrigation. Unfavorable weather conditions shortly after silking in 1996 (low irradiation in combination with relatively high temperature) seemed to have limited the grain yield of well-watered DK888. It is hypothesized that the adverse effects of pre-anthesis drought on grain yield can be mitigated if varieties are selected for roots which rapidly penetrate the soil and exploit the water resources in deep soil layers.
Published in: Agricultural water management
Volume: 81
Issue: 1-2
Pages: 41 - 58
ISSN: 0378-3774
Publication date / Date received: 2006-01-01
Publication status: Amsterdam
Publication status: Published
Subjects: Landwirtschaft allgemein|Agriculture, General, Harvest index, Tropical maize, Nitrogen fertilization, Pre-anthesis water stress, Yield components
Language: English
Review status: Peer reviewed
Keyword: Harvest index, Tropical maize, Nitrogen fertilization, Pre-anthesis water stress, Yield components
DBID source: PP-28142, WOS-000235861100003
DOI: 10.1016/j.agwat.2005.04.005
Nebis system number: 000000988
, Messmer, Rainer Ernst, 2006 >>
Author(s): Messmer, Rainer Ernst
Title: The genetic dissection of key factors involved in the drought tolerance of tropical maize (Zea mays L.)
Abstract: Maize is an important source of human nutrition, especially in the tropics, where most of the maize is grown under rain-fed conditions and where drought is a major constraint to agricultural production. Sub-Saharan Africa is currently one of the most severely affected regions and the occurrence of drought spells is predicted to increase in the future. The development of more drought-tolerant genotypes can contribute to ensure food security in this area and worldwide. However, selection for drought tolerance is difficult because of the unpredictability of stress under natural conditions, because of the occurrence of strong interactions between genotypes and the environment and because of limited knowledge about the role and regulation of tolerance mechanisms. Classical approaches to breeding have identified secondary traits for grain yield under drought stress. Most of these traits are polygenic, but grain yield probably remains the most polygenic and complex trait. The genetic control of polygenic and complex traits is mainly quantitative. The mapping of quantitative trait loci (QTLs) is, therefore, a promising tool for detecting genomic regions controlling polygenic trait expression as well as for studying changes in the expression of these loci across varying environmental conditions. The goal of this project was to provide an understanding of the genetic basis of morphological and physiological traits involved in response to water-limited conditions at flowering of two tropical maize lines with different levels of drought tolerance. The target regions identified by QTL mapping will contribute to complementing the evaluation and selection of improved germplasm, especially in sub-Saharan Africa. To achieve this goal, a genetic linkage map was constructed for a population of recombinant inbred lines (RILs). These lines were developed by crossing the drought-tolerant tropical maize line CML444 (PL1) with the droughtsusceptible tropical maize line SC-Malawi (PL2) and five generations of inbreeding. The genetic linkage map consisted of the allelic segregation of 236 RILs at 160 molecular marker loci. The map was 2105 cM long and had an average distance between two consecutive markers of 13.2 cM. The RIL population and the parental lines were evaluated in a total of 11 field experiments in Mexico and Zimbabwe. The experiments were performed in 2003 and 2004 under managed drought stress at flowering (D) or under rain-fed conditions (W) with sufficient water supply. The plants were phenotyped for flowering time, plant height, chlorophyll content of two leaves, leaf senescence and root capacitance as well as for the dry weight of the tassels, ears and silks during the critical stress period; grain yield parameters were measured at maturity. The QTLs were identified by composite interval mapping. Drought stress caused large reductions in total grain yield and, correlatively, in kernel number per area compared to the highest-yielding experiment under rain-fed conditions in Zimbabwe (WZ1). Grain yield (GYA) was controlled by only a few QTLs, whose effects on trait expression were larger and more significant under rain-fed conditions than under drought. The QTLs for GYA showed strong interactions with the environment (QEI) and changed their positions on the genome across environments. The strong genetic control of hundred kernel weight (HKW), in contrast, was stable and unrelated to that of grain yield. The anthesis-silking interval (ASI), a common secondary trait for grain yield under drought, was negatively correlated with GYA both within and across experiments. However, QTLs with direct effects on both traits were not observed under drought stress. The QTL on chromosome 1 close to marker 15 (c1m15) was the only locus that controlled ASI in more than one environment. It was detected between the QTL c1m11, with a large positive additive effect on grain yield in the high-yielding and rain-fed experiment in Zimbabwe and with negative effects on plant height (PHT) in the other environments, and the QTL c1m17 controlling male flowering time (MFL) and ear dry weight at anthesis (EW0). Contrary to expectations, the allele of the drought-tolerant parent (PL1) was associated with an increase in ASI, which is unfavorable under drought stress. The effect of these QTLs on chromosome 1 on trait expression demonstrated that GYA was more closely associated genetically with PHT and that ASI was more closely related with MFL than was GYA with ASI in this tropical maize population. The PL1 realized its high yield potential only under rainfed conditions and showed larger drought-induced yield reductions than PL2. Nevertheless, PL1 produced more grains than PL2 in the drought-stress experiments, but the differences between the two lines were smaller than in the rain-fed experiments and not always significant. Drought stress concomitantly reduced the PHT of PL1 to a greater extent than the PHT of PL2; MFL of PL1 was delayed. Apparently, PL2 escaped drought stress through early maturity when exposed to water-limited conditions at flowering. Considering these distinct phenotypic responses of the two parental lines to water shortage, the QTLs for GYA, PHT, ASI, MFL and EW0, detected on chromosomes 1 and 3, but also the QTLs for MFL and leaf chlorophyll content on chromosome 2, revealed the important genetic basis of the morpho-physiological differences between the two parental lines. Each of the morpho-physiological traits evaluated in this study, including root capacitance (RCT) and tassel dry weight (TBW), was controlled by at least one QTL detected in more than one environment, which suggested that all the traits were controlled by some intrinsic genes. However, not all of these genes were constitutively expressed in all experiments. MFL, in particular, was under strong genetic control. The four most important QTLs for this trait corresponded to universal QTLs for flowering time in maize. TBW did not influence MFL, but there was a weak negative correlation between TBW and ear dry weight at anthesis (EW0). This correlation suggested that selection for small tassels could increase the flux of assimilates to the ear before and during the critical period at flowering. However, such an effect would be small, because the phenotypic correlation was weak and the dry weight of the male and the female inflorescences were controlled by distinct QTLs. The phenotypic response of the parental lines to drought stress in terms of EW0 showed notable similarities to GYA. The phenotypic differences between the two lines were largest under rain-fed conditions and PL1 showed larger drought-stress-induced reductions in EW0 than PL2. Nevertheless, the QTL c3m7, important for the dry weight of the ears and silks at flowering under drought-stressed conditions, was not detected for grain yield. Co-locating QTLs for grain yield and for physiological secondary traits, such as the anthesis-silking interval, dry weight of the ears and silks at anthesis, leaf chlorophyll content and leaf senescence, but also for plant height were observed on chromosomes 8, 9 and 10. The pattern of QTL expression across experiments, together with the additive effects of the PL1 allele, suggested the presence of stress-adaptive genes. Their effect on drought-tolerance mechanisms contrasted with the effect of the rather structural and constitutive QTLs located on chromosomes 1, 2 and 3. Therefore, the middle sections of chromosomes 8, 9 and, in particular, the middle section of chromosome 10 were identified as potential target regions for marker-assisted selection (MAS) for improving drought tolerance. The QTL regions on the middle sections of chromosomes 1, 2 and 3 should also be used for MAS, since the effects of the respective QTLs on vegetative growth, organ development and other plant characteristics such as leaf chlorophyll content suggested that functional gene clustering can be expected in maize. This would be an important prerequisite for the development and the successful application of novel MAS techniques without the common drawbacks of MAS, namely cross specificity and the narrow range of target environments.
Publication date / Date received: 2006-01-01
Publication status: Zürich
Publication status: Published
Language: English
Review status: Unknown
ETH dissertation number: 16695
DBID source: PP-32512
DOI: 10.3929/ethz-a-005273099
Nebis system number: 005273099
, Eschholz, T.W., Peter, R., Stamp, P., Hund, A., 2006 >>
Author(s): Eschholz, T.W., Peter, R., Stamp, P., Hund, A.
Title: Swiss maize landraces
Subtitle: Their diversity and genetic relationships
Abstract: Genetic variation in the flint maize (Zea mays L. conv. indurata) gene pool has decreased significantly since the introduction of hybrid breeding into Europe in the 1950s, leading to greater genetic vulnerability. Landraces, stored in gene banks, offer a valuable source to broaden the genetic basis again. The objective of this study was the genetic characterization of 166 Swiss landrace accessions originating from 7 Swiss regions (alpine valleys). The material was fingerprinted using a set of ten SSRs (Simple Sequence Repeat Markers). The resulting cladogram showed three main clusters comprising 95, 22 and 49 accessions, respectively. The largest group of accessions, from the Rhine valley of St. Gallen (RT), was present in all three main clusters. However, the majority of RT accessions was found in the first main cluster, together with those from the western neighbouring region (Linthtal) and from the southwestern neighbouring region (Wallis). Those from Tessin (southern Switzerland) were found mainly in one sub-cluster within the third main cluster. This is a very encouraging first step in appraising the genetic differences among accessions from Swiss regions.
Published in: Acta agronomica Hungarica
Volume: 54
Issue: 3
Pages: 321 - 328
ISSN: 1588-2527, 0238-0161
Publication date / Date received: 2006-01-01
Publication status: Budapest
Publication status: Published
Subjects: Switzerland, flint maize, genetic distance, Zea mays L., SSR markers, landraces
Language: English
Review status: Peer reviewed
Keyword: Switzerland, flint maize, genetic distance, Zea mays L., SSR markers, landraces
DBID source: PP-28130
DOI: 10.1556/AAgr.54.2006.3.6
, Tschannen, A. B., Escher, F., Stamp, P., 2005 >>
Author(s): Tschannen, A. B., Escher, F., Stamp, P.
Title: Post-harvest treatment of seed tubers with gibberellic acid and field performance of yam (Dioscorea cayenensis-rotundata) in Ivory Coast
Abstract: Tubers of white yam (Dioscorea cayenensis-rotundata) are often cut into segments for planting, so-called setts, whose weight and quality strongly influence yield. The effect of a post-harvest gibberellic acid treatment or manual desprouting of seed tubers on the quality of setts was investigated in a combined storage and field experiment over two years in central Ivory Coast. Although post-harvest losses were slightly reduced after four months of storage by both treatments, this had no effect on tuber yield. However, emergence and yield were significantly influenced by both the sprouting state at planting and the origin of a sett with respect to its position on the mother tuber. Limited resources should therefore be directed to apical scuts and sprouted setts which have the highest yield potential. A GA(3)-derived distortion of the spatial distribution of sprouting loci leads to a more homogenous yield for setts of different origins.
Published in: Experimental agriculture
Volume: 41
Issue: 2
Pages: 175 - 186
ISSN: 0014-4797, 1469-4441
Publication date / Date received: 2005-01-01
Publication status: Cambridge
Publication status: Published
Language: English
Review status: Peer reviewed
DBID source: WOS-000229269800003, PP-17720, PP-23381
DOI: 10.1017/S0014479704002455
Nebis system number: 000009488
, Schelbert, R., Sangakkara, U.R., Stamp, P., 2005 >>
Author(s): Schelbert, R., Sangakkara, U.R., Stamp, P.
Title: Maize yields as affected by short- and long-term improved fallows
Subtitle: A comparative analysis in the Asian humid tropics
Abstract: Improved short- or long-term fallows are considered suitable low external input technologies for maintaining productivity and sustainability of tropical smallholder upland cropping units, although comparisons on the benefits of this technology are not widely reported. A field study evaluated the impact of improved short (6 months) and long-term fallow (18 months) using Crotalaria juncea and Tithonia diversifolia, in relation to a natural fallow of the same durations, on the productivity of maize (Zea mays), the most important upland cereal in tropical Asia, over a minor season. The use of improved fallows, especially Tithonia, increased maize yields over the Crotalaria or natural fallow. While the overall yields of maize after a long fallow were greater, the beneficial impact of the green manures was significantly higher in the short fallows. The causal factors for this trend, including biomass production of the improved fallows and possible impact on soils, along with the greater benefits of short-term fallows for increasing maize yields in the tropics due to lower requirements of unproductive time are presented.
Published in: Journal of agronomy and crop science
Volume: 191
Issue: 6
Pages: 411 - 415
ISSN: 0931-2250, 0044-2151, 1439-037X
Publication date / Date received: 2005-01-01
Publication status: Berlin
Publication status: Published
Subjects: Crotalaria, fallow periods, maize, Tithonia, yields
Language: English
Review status: Peer reviewed
Keyword: Crotalaria, fallow periods, maize, Tithonia, yields
DBID source: PP-17728
DOI: 10.1111/j.1439-037X.2005.00183.x
Nebis system number: 000033963
, Qin, Ruijun, Stamp, Peter, Richner, Walter, 2005 >>
Author(s): Qin, Ruijun, Stamp, Peter, Richner, Walter
Title: Impact of Tillage and Banded Starter Fertilizer on Maize Root Growth in the Top 25 Centimeters of the Soil
Abstract: There is little information about root growth response to tillage and starter fertilization in cool temperate regions. Maize (Zea mays L.) root morphology and distribution at anthesis were studied in 1997 and 1999 at two sites in the Swiss Midlands on a loamy silt and a sandy loam soil. The effects of tillage system, conventional tillage (CT) vs. no-tillage (NT), and starter fertilizer (SF) banded to one side of the seed row were evaluated. Roots were determined in soil cores taken 9.5 cm on each side of the seed row and 25 cm deep. The overall root length density (RLD) was significantly greater under CT than under NT on the loamy silt soil but not on the sandy loam soil. In NT, RLD tended to be greater than in CT in the uppermost 5 to 10 cm of the soil but less in deeper soil. Mean root diameter (MD) under CT was smaller than under NT for both years and sites. In 1997, banded SF (BSF) improved RLD in the SIT bands compared with the opposite side of the seed row; in 1999, this effect happened only in the uppermost soil layers (0 to 5 cm) in NT. Banded SF tended to increase MD in three combinations of year and site and to decrease it in Schafisheim 1999. Overall, this research indicates that the effects of tillage and BSF on root growth of maize at flowering were in accordance with the previous findings on early root growth. However, root growth response to tillage and SF is complex and often a function of year, soil type, and depth.
Published in: Agronomy journal
Volume: 97
Issue: 3
Pages: 674 - 683
Publication date / Date received: 2005-01-01
Publication status: Madison, WI
Publication status: Published
Language: English
Review status: Peer reviewed
DBID source: WOS-000229388100005, PP-17721
DOI: 10.2134/agronj2004.0059
Nebis system number: 000036236
, Pasini, Luca, Bruschini, Stefania, Bertoli, Alessia, Mazza, Raffaele, Fracheboud, Yvan, Marocco, Adriano, 2005 >>
Author(s): Pasini, Luca, Bruschini, Stefania, Bertoli, Alessia, Mazza, Raffaele, Fracheboud, Yvan, Marocco, Adriano
Title: Photosynthetic performance of cold-sensitive mutants of maize at low temperature
Abstract: The virescent character is a genetic variant in pigmentation characterized by a delay in greening. Seedlings of the virescent mutants v1, v2, v3, v4, v13, v16, v18, v19 and v26 of maize exhibit chlorosis when grown at low temperature. Chlorotic leaves contain plastids that appear to have been arrested at an early stage of development. The results indicated that V16, V2, V3 and V4 loci control early stages of chloroplast development while V1, V13 and V19 may play a role at the end of development. The mutations in the V18 and V26 loci may control an intermediate step. At the pigment level, the virescent mutants of maize differ widely from analogous mutations existing in other plants. The mutations were characterized by a reduced amount of chlorophyll a and b (up to 100 times in v16) and chlorophyll a/b ratio above normal (up to 13.7 in v16). Lutein content was reduced in all mutants (less than 3% in v16 compared to wild type) but v13, while pigments of the xanthophyll cycle were found at higher levels in v1 and v13 (more than 10 and 90%, respectively). The v2, v3, v4, v16 and v18 mutants that are most depleted in beta-carotene (36 times less in average than wild type) are also deprived in D1 and D2 polypeptides. Moreover, the v2, v3, v4, v16 and v18 mutants characterized by a lower accumulation in lutein are most depleted of light-harvesting complex II. All mutants possess a functioning, fully reversible, non-photochemical quenching mechanism. This is most developed in the v13 and v19 mutants (phi(n) = 0.48 and 0.44, respectively). These two mutants also have a relatively high primary photochemical yield for photosystem II and a functioning photosystem I (phi(p) = 0.23 and 0.39, respectively). The most interesting mutant is v13 that shows severe chlorosis and possesses the most effective non-photochemical quenching mechanism(s), which is thought to provide protection against excess photon absorption by photosystem II.
Published in: Physiologia plantarum
Volume: 124
Issue: 3
Pages: 362 - 370
Publication date / Date received: 2005-01-01
Publication status: Oxford
Publication status: Published
Language: English
Review status: Peer reviewed
DBID source: WOS-000229977800009, PP-17892
DOI: 10.1111/j.1399-3054.2005.00522.x
Nebis system number: 000471614
, Jompuk, Choosak, Fracheboud, Yvan, Stamp, Peter, Leipner, Jörg, 2005 >>
Author(s): Jompuk, Choosak, Fracheboud, Yvan, Stamp, Peter, Leipner, Jörg
Title: Mapping of quantitative trait loci associated with chilling tolerance in maize (Zea mays L.) seedlings grown under field conditions
Abstract: The effect of low growth temperature on morpho-physiological traits of maize was investigated by the means of a QTL analysis in a segregating F-2:3 population grown under field conditions in Switzerland. Chlorophyll fluorescence parameters, leaf greenness, leaf area, shoot dry weight, and shoot nitrogen content were investigated at the seedling stage for two years. Maize was sown on two dates in each year; thus, plants sown early were exposed to low temperature, whereas those sown later developed under more favourable conditions. The main QTLs involved in the functioning of the photosynthetic apparatus at low temperature were stable across the cold environments and were also identified under controlled conditions with suboptimal temperature in a previous study. Based on the QTL analysis, relationships between chlorophyll fluorescence parameters and leaf greenness were moderate. This indicates that the extent and functioning of the photosynthetic machinery may be under different genetic control. The functioning of the photosynthetic apparatus in plants developed at low temperature in the field did not noticeably affect biomass accumulation; since there were no co-locations between QTLs for leaf area and shoot dry weight, biomass accumulation did not seem to be carbon-limited at the seedling stage under cool conditions in the field.
Published in: Journal of experimental botany
Volume: 56
Issue: 414
Pages: 1153 - 1163
ISSN: 0022-0957, 1460-2431
Publication date / Date received: 2005-01-01
Publication status: Oxford
Publication status: Published
Subjects: Chilling tolerance, Chlorophyll fluorescence, Field environment, Maize, Photosynthesis, QTL, Seedling vigour
Language: English
Review status: Peer reviewed
Keyword: Chilling tolerance, Chlorophyll fluorescence, Field environment, Maize, Photosynthesis, QTL, Seedling vigour
DBID source: WOS-000227975900008, PP-17083
DOI: 10.1093/jxb/eri108
Nebis system number: 000049325
, Hund, Andreas, Frascaroli, Elisabetta, Leipner, Jörg, Jompuk, Choosak, Stamp, Peter, Fracheboud, Yvan, 2005 >>
Author(s): Hund, Andreas, Frascaroli, Elisabetta, Leipner, Jörg, Jompuk, Choosak, Stamp, Peter, Fracheboud, Yvan
Title: Cold Tolerance of the Photosynthetic Apparatus
Subtitle: Pleiotropic Relationship between Photosynthetic Performance and Specific Leaf Area of Maize Seedlings
Abstract: The objective of this study was to elucidate the genetic relationship between the specific leaf area (SLA) and the photosynthetic performance of maize (Zea mays L.) as dependent on growth temperature. Three sets of genotypes: (i) 19 S-5 inbred lines, divergently selected for high or low operating efficiency of photosystem II (Phi(PSII)) at low temperature, (ii) a population of 226 F-2:3 families from the cross of ETH-DL3 x ETH-DH7, and (iii) a population of 168 F-2:4 families from the cross of Lo964 x Lo1016 were tested at low (15/13 degrees C day/night) or at optimal (25/22 degrees C day/night) temperature. The latter cross was originally developed to study QTLs for root traits. At 15/13 degrees C the groups of S-5 inbred lines selected for high or low Phi(PSII) differed significantly for all the measured traits, while at optimal temperature the groups differed only with regard to leaf greenness (SPAD). At low temperature, the SLA of these inbred lines was negatively correlated with Phi(PSII) (r=-0.56, p < 0.05) and SPAD (r=-0.80, p < 0.001). This negative relationship was confirmed by mapping quantitative trait loci (QTL) in the two mapping populations. A co-location of three QTLs for SLA with QTLs for photosynthesis-related traits was detected in both populations at 15/13 degrees C, while co-location was not detected at 25/22 degrees C. The co-selection of SLA and Phi(PSII) in the inbred lines and the co-location of QTL for SLA, SPAD, and Phi(PSII) at 15/13 degrees C in the QTL populations strongly supports pleiotropy. There was no evidence that selecting for high Phi(PSII) at low temperature leads to a constitutively altered SLA.
Published in: Molecular breeding
Volume: 16
Issue: 4
Pages: 321 - 331
ISSN: 1380-3743, 1572-9788
Publication date / Date received: 2005-01-01
Publication status: Berlin
Publication status: Published
Subjects: chilling stress, chlorophyll fluorescence, quantitative trait locus (QTL), specific leaf area, Zea mays
Language: English
Review status: Peer reviewed
Keyword: chilling stress, chlorophyll fluorescence, quantitative trait locus (QTL), specific leaf area, Zea mays
DBID source: WOS-000233739000006, PP-17756
DOI: 10.1007/s11032-005-1642-7
Nebis system number: 001430119
, Hiltbrunner, Jürg, Liedgens, Markus, Stamp, Peter, Streit, Bernhard, 2005 >>
Author(s): Hiltbrunner, Jürg, Liedgens, Markus, Stamp, Peter, Streit, Bernhard
Title: Effects of row spacing and liquid manure on directly drilled winter wheat in organic farming
Abstract: In the optimisation of grain yield and quality of wheat, plant distribution is a key factor. In contrast to high yield levels, at moderate levels. widening the row space did not decrease grain yield. To gain information about changes in the quality and yield with changing in row spacings in organic farming systems, experiments were conducted at two locations in the Swiss midlands in 2001/2002. Winter wheat (Triticum aestivum L., cv. Titlis) was directly drilled in rows 0.1875 and 0.3750 in apart at the same seeding rate per area. An unfertilised treatment and the usual application of 60 m(3) ha(-1) liquid farmyard manure were compared. While the grain yield was not decreased by the wider row spacing, the thousand kernel weight (TKW), and grain protein content were increased from 42.6 to 43.5 a and from 11.7 to 12.7 %, respectively, compared to the narrow row spacing. Liquid manure, on average of both experimental sites, increased the yield (from 3.725 to 4.765 Mg ha(-1)) and the grain protein content (from 12.0 to 12.5 %). Doubling the space between the rows from 0.1875 to 0.3750 in seemed to be a suitable strategy for managing directly drilled winter wheat in organic farming systems.
Published in: European journal of agronomy
Volume: 22
Issue: 4
Pages: 441 - 447
ISSN: 1161-0301
Publication date / Date received: 2005-01-01
Publication status: Amsterdam
Publication status: Published
Subjects: Agrar- und Forstwissenschaften|Agriculture and Forestry, Winter wheat, Organic farming, Direct drilling, Row spacing, Central Europe
Language: English
Review status: Peer reviewed
Keyword: Winter wheat, Organic farming, Direct drilling, Row spacing, Central Europe
DBID source: WOS-000229193900006, PP-17719
DOI: 10.1016/j.eja.2004.06.003
Nebis system number: 000650747
, Herrera, Juan M., Stamp, Peter, Liedgens, Markus, 2005 >>
Author(s): Herrera, Juan M., Stamp, Peter, Liedgens, Markus
Title: Root development of catch crops and nitrate losses by leaching after spring wheat
Book title: Roots and the soil environment II
Published in: Aspects of applied biology
Volume: 73
Pages: 35 - 40
ISSN: 0265-1491
Publication date / Date received: 2005-01-01
Publication status: Wellesbourne, Warwick
Publication status: Published
Event name: Roots and the soil environment II
Event date: April 4-6, 2005
Place: Nottingham, UK
Language: English
Review status: Peer reviewed
DBID source: PP-17717
Nebis system number: 004984114
, Herrera, J.M., Stamp, P., Liedgens, M., 2005 >>
Author(s): Herrera, J.M., Stamp, P., Liedgens, M.
Title: Dynamics of root development of spring wheat genotypes varying in nitrogen use efficiency
Book title: Roots and the soil environment II : University of Nottingham, Sutton Bonington, 4-6 April 2005
Published in: Aspects of applied biology
Volume: 73
Pages: 27 - 33
Publication date / Date received: 2005-01-01
Publication status: Wellesbourne, Warwick
Publication status: Published
Subjects: Spring wheat, Nitrogen, Roots, Minithizotrons
Event name: Roots and the soil environment II
Event date: April 4-6, 2005
Place: Nottingham, UK
Language: English
Review status: Peer reviewed
Keyword: Spring wheat, Nitrogen, Roots, Minithizotrons
DBID source: PP-17715
Nebis system number: 004984114
, Feil, B., Moser, S. B., Jampatong, S., Stamp, P., 2005 >>
Author(s): Feil, B., Moser, S. B., Jampatong, S., Stamp, P.
Title: Mineral composition of the grains of tropical maize varieties as affected by pre-anthesis drought and rate of nitrogen fertilization
Abstract: Breeding for higher concentrations of minerals in food crops is one option for improving the health of humans suffering from the consequences of mineral deficiency. The plant breeding approach requires that varietal differences are stable across different environmental conditions. The main objective of our research was, therefore, to determine whether differences in the concentration of grain minerals (P, K, Mg, Ca, Mn, Zn, and Cu) among tropical maize varieties are affected by the level of water and N supply. A 3-yr study with two water regimes (preanthesis drought vs. irrigation throughout the vegetation cycle), three levels of N fertilization (0, 80, 160 kg N ha(-1), applied as ammonium sulfate), and four varieties (Suwan 1, La Posta Sequia, KTX2602, DK888) was conducted in the tropical lowlands of Thailand. The water regime did not affect the mineral composition of the grains. Application of N fertilizer reduced the concentrations of Ca and Zn, and increased the concentration of Mn in the grains. The top yielder, DK888, had the lowest concentrations of N, P, Mg, and Cu in the grain. The varietal differences in the concentrations of grain N and minerals were fairly stable across the levels of N and preanthesis water supply. The varieties that differed most in the grain N and P concentrations (DK888 and KTX2602) had almost the same endosperm/germ dry weight ratio. It remains to be determined whether breeding for high grain yield inevitably lowers the concentrations of grain minerals and protein.
Published in: Crop science
Volume: 45
Issue: 2
Pages: 516 - 523
ISSN: 0011-183X
Publication date / Date received: 2005-01-01
Publication status: Madison, WI
Publication status: Published
Language: English
Review status: Peer reviewed
DBID source: WOS-000227602700013, PP-17714
DOI: 10.2135/cropsci2005.0516
Nebis system number: 000036710
, Aguilar, V., Stamp, P., Winzeler, M., Schachermayr, G., Keller, B., Zanetti, S., Messmer, M.M., 2005 >>
Author(s): Aguilar, V., Stamp, P., Winzeler, M., Schachermayr, G., Keller, B., Zanetti, S., Messmer, M.M.
Title: Inheritance of field resistance to Stagonospora nodorum leaf and glume blotch and correlations with other morphological traits in hexaploid wheat (Triticum aestivum L.)
Abstract: Breeding for wheat varieties resistant to Stagonospora nodorum blotch (SNB) is the most sustainable strategy for controlling the disease. In order to map quantitative trait loci (QTLs) for SNB resistance we analysed 204 recombinant inbred lines of the cross between the winter wheat (Triticum aestivum L.) variety Forno and the winter spelt (Triticum spelta L.) variety Oberkulmer. We determined the level of resistance of adult plants to leaf blotch (SNL) and glume blotch (SNG) as well as morphological traits for 2 years after artificial inoculation with S. nodorum. Using composite interval mapping and LOD > 3.7, we detected ten QTLs for SNG blotch resistance (six inherited from the susceptible parent Forno) and 11 QTLs for SNL resistance (four inherited from Forno) across 2 years. Both resistance traits were moderately correlated (r=0.52) and had only one common QTL. For SNL resistance, seven QTLs were not associated with QTLs for morphological traits. Among them, QSnl.eth-2D, QSnl.eth-4B and QSnl.eth-7B3 had major effects (R-2> 13%) and were potential candidates for marker-assisted selection. For SNG, the major QTL on chromosome 5A, explaining 36% of the phenotypic variance for resistance, was associated with the q locus conferring the spelt morphology (long lax ear, long culm and hard glumes). Only QSng.eth-1BS, which explained 7% of the variance for resistance to SNG blotch, was not associated with QTLs for morphological traits. The consequences for breeding programmes are discussed.
Published in: Theoretical and applied genetics
Volume: 111
Issue: 2
Pages: 325 - 336
ISSN: 0040-5752, 1432-2242
Publication date / Date received: 2005-01-01
Publication status: Berlin
Publication status: Published
Subjects: Triticum, Stagonospora nodorum, field resistance, QTL
Language: English
Review status: Peer reviewed
Keyword: Triticum, Stagonospora nodorum, field resistance, QTL
DBID source: WOS-000230689800015, PP-17724
DOI: 10.1007/s00122-005-2025-5
Nebis system number: 000985869
, Fournier, Jerome Marc, Stamp, Peter, Bolanõs, Jorge, 2004 >>
Author(s): Fournier, Jerome Marc, Stamp, Peter, Bolanõs, Jorge
Title: Prediction of maize grain yield using the chlorophyll meter technique in the Polochic Watershed of Guatemala
Abstract: Growers of tropical maize (Zea mays L.) are often reluctant to invest in seeds and fertilizers because they are seeking to minimize risks. A chlorophyll meter measures leaf greenness, which non-destructively indicates the leaf N concentration. This may be an alternative to sampling N in the soil and to analyzing N in plant tissue, both of which are costly methods for estimating the N status of a crop at a certain growth stage. Thus, at earlier growth stages, the N status of a crop could be related to the final yield. At early growth stages of maize, the chlorophyll meter has been used successfully to predict the yield in many regions. In this study, a Minolta chlorophyll meter (type SPAD 502) was calibrated to distinguish between two maize varieties [Local Variety and HB-83 (a white hybrid)] and three fertilizer treatments [zero, recommended (89:13:24 N:P:K kg ha(-1)), and supra optimum (151:37:76)]. The meter was more useful at lower than at higher levels of fertilization, where SPAD readings as estimates of chlorophyll content appeared to reach a plateau. Both linear and quadratic relationships were observed between SPAD readings and maize grain yields. Central American farmers often apply low levels of fertilizers. If chlorophyll meter readings were to diagnose N deficiency accurately and inexpensively, fertilizers could be applied late in the season to counteract N deficiency. The chlorophyll meter should be calibrated for each variety in order to predict the yield with sufficient precision.
Published in: Tropical agriculture
Volume: 81
Issue: 2
Pages: 95 - 100
ISSN: 0041-3216
Publication date / Date received: 2004-01-01
Publication status: Trinidad
Publication status: Published
Subjects: maize, grain yield prediction, N deficiency, minolta chlorophyll meter, linear and, quadratic relationships
Language: English
Review status: Peer reviewed
Keyword: maize, grain yield prediction, N deficiency, minolta chlorophyll meter, linear and, quadratic relationships
DBID source: PP-17723, WOS-000202872800006
Nebis system number: 000000737

 

 

 

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